diff --git a/include/xlnt/cell/cell_value.h b/include/xlnt/cell/cell_value.h
new file mode 100644
index 00000000..6bd4a9c9
--- /dev/null
+++ b/include/xlnt/cell/cell_value.h
@@ -0,0 +1,98 @@
+// Copyright (c) 2014 Thomas Fussell
+// Copyright (c) 2010-2014 openpyxl
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE
+//
+// @license: http://www.opensource.org/licenses/mit-license.php
+// @author: see AUTHORS file
+#pragma once
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+#include "../styles/style.hpp"
+#include "../common/types.hpp"
+
+namespace xlnt {
+
+struct date;
+struct datetime;
+struct time;
+
+class cell_value
+{
+public:
+    enum class type
+    {
+        null,
+        numeric,
+        string,
+        formula,
+        boolean,
+        error
+    };
+
+    std::string to_string() const;
+
+    type get_data_type() const;
+
+    void set_null();
+
+    cell_value &operator=(const cell_value &rhs);
+    cell_value &operator=(bool value);
+    cell_value &operator=(int value);
+    cell_value &operator=(double value);
+    cell_value &operator=(long int value);
+    cell_value &operator=(long long value);
+    cell_value &operator=(long double value);
+    cell_value &operator=(const std::string &value);
+    cell_value &operator=(const char *value);
+    cell_value &operator=(const date &value);
+    cell_value &operator=(const time &value);
+    cell_value &operator=(const datetime &value);
+
+    bool operator==(const cell_value &comparand) const;
+    bool operator==(std::nullptr_t) const;
+    bool operator==(bool comparand) const;
+    bool operator==(int comparand) const;
+    bool operator==(double comparand) const;
+    bool operator==(const std::string &comparand) const;
+    bool operator==(const char *comparand) const;
+    bool operator==(const date &comparand) const;
+    bool operator==(const time &comparand) const;
+    bool operator==(const datetime &comparand) const;
+
+    friend bool operator==(std::nullptr_t, const cell_value &cell);
+    friend bool operator==(bool comparand, const cell_value &cell);
+    friend bool operator==(int comparand, const cell_value &cell);
+    friend bool operator==(double comparand, const cell_value &cell);
+    friend bool operator==(const std::string &comparand, const cell_value &cell);
+    friend bool operator==(const char *comparand, const cell_value &cell);
+    friend bool operator==(const date &comparand, const cell_value &cell);
+    friend bool operator==(const time &comparand, const cell_value &cell);
+    friend bool operator==(const datetime &comparand, const cell_value &cell);
+};
+
+inline std::ostream &operator<<(std::ostream &stream, const xlnt::cell_value &value)
+{
+    return stream << value.to_string();
+}
+
+} // namespace xlnt
diff --git a/include/xlnt/common/datetime.hpp b/include/xlnt/common/datetime.hpp
index 41b0943c..3ba22690 100644
--- a/include/xlnt/common/datetime.hpp
+++ b/include/xlnt/common/datetime.hpp
@@ -26,6 +26,12 @@
 
 namespace xlnt {
 
+enum calendar
+{
+    windows_1900,
+    mac_1904
+};
+
 struct date
 {
     static date today();
diff --git a/include/xlnt/common/zip_file.hpp b/include/xlnt/common/zip_file.hpp
index 60fb8b8f..14d54e27 100644
--- a/include/xlnt/common/zip_file.hpp
+++ b/include/xlnt/common/zip_file.hpp
@@ -95,8 +95,8 @@ public:
     zip_file(const std::string &filename, file_mode mode, file_access access = file_access::read);
     
     ~zip_file();
-    
-    std::string get_file_contents(const std::string &filename);
+
+    std::string get_file_contents(const std::string &filename) const;
     
     void set_file_contents(const std::string &filename, const std::string &contents);
     
diff --git a/include/xlnt/reader/reader.hpp b/include/xlnt/reader/reader.hpp
index fb287307..3f9e0cde 100644
--- a/include/xlnt/reader/reader.hpp
+++ b/include/xlnt/reader/reader.hpp
@@ -32,7 +32,9 @@ namespace xlnt {
     
 class workbook;
 class worksheet;
-    
+class document_properties;
+class zip_file;
+
 class reader
 {
 public:
@@ -44,6 +46,8 @@ public:
     static void read_worksheet(worksheet ws, const std::string &xml_string, const std::vector<std::string> &string_table);
     static std::vector<std::string> read_shared_string(const std::string &xml_string);
     static std::string read_dimension(const std::string &xml_string);
+    static document_properties read_properties_core(const std::string &xml_string);
+    static std::vector<std::pair<std::string,std::string>> read_sheets(const zip_file &archive);
 };
     
 } // namespace xlnt
diff --git a/include/xlnt/workbook/workbook.hpp b/include/xlnt/workbook/workbook.hpp
index 91987eb8..3003359d 100644
--- a/include/xlnt/workbook/workbook.hpp
+++ b/include/xlnt/workbook/workbook.hpp
@@ -62,6 +62,9 @@ public:
     workbook(const workbook &) = delete;
     
     void read_workbook_settings(const std::string &xml_source);
+
+    void create_relationship(const std::string &id, const std::string &target, const std::string &type);
+    relationship get_relationship(const std::string &id) const;
     
     //getters
     worksheet get_active_sheet();
diff --git a/include/xlnt/writer/writer.hpp b/include/xlnt/writer/writer.hpp
index bcd5ee8d..d82f9822 100644
--- a/include/xlnt/writer/writer.hpp
+++ b/include/xlnt/writer/writer.hpp
@@ -24,12 +24,15 @@
 #pragma once
 
 #include <string>
+#include <unordered_map>
+#include <utility>
 #include <vector>
 
 namespace xlnt {
     
 class workbook;
 class worksheet;
+class document_properties;
     
 class writer
 {
@@ -44,6 +47,8 @@ public:
     static std::string write_workbook_rels(const workbook &wb);
     static std::string write_worksheet_rels(worksheet ws, int drawing_id, int comments_id);
     static std::string write_string_table(const std::vector<std::string> &string_table);
+    static std::string write_properties_core(const document_properties &prop);
+    static std::string write_properties_app(const workbook &wb);
 };
     
 } // namespace xlnt
diff --git a/include/xlnt/xlnt.hpp b/include/xlnt/xlnt.hpp
index 406dea10..ed368d75 100644
--- a/include/xlnt/xlnt.hpp
+++ b/include/xlnt/xlnt.hpp
@@ -44,3 +44,5 @@ const std::string download_url = "https://github.com/tfussell/xlnt/archive/maste
 #include "common/exceptions.hpp"
 #include "reader/reader.hpp"
 #include "common/string_table.hpp"
+#include "common/zip_file.hpp"
+#include "workbook/document_properties.hpp"
diff --git a/source/document_properties.cpp b/source/document_properties.cpp
new file mode 100644
index 00000000..b47d378d
--- /dev/null
+++ b/source/document_properties.cpp
@@ -0,0 +1,10 @@
+#include "workbook/document_properties.hpp"
+
+namespace xlnt {
+
+document_properties::document_properties() : created(1900, 1, 1), modified(1900, 1, 1)
+{
+
+}
+
+} // namespace xlnt
\ No newline at end of file
diff --git a/source/reader.cpp b/source/reader.cpp
index f642cceb..4240d2c9 100644
--- a/source/reader.cpp
+++ b/source/reader.cpp
@@ -7,9 +7,36 @@
 #include "worksheet/range_reference.hpp"
 #include "workbook/workbook.hpp"
 #include "worksheet/worksheet.hpp"
+#include "workbook/document_properties.hpp"
+#include "common/zip_file.hpp"
 
 namespace xlnt {
 
+std::vector<std::pair<std::string, std::string>> reader::read_sheets(const zip_file &archive)
+{
+    auto xml_source = archive.get_file_contents("xl/workbook.xml");
+    pugi::xml_document doc;
+    doc.load(xml_source.c_str());
+    std::vector<std::pair<std::string, std::string>> sheets;
+    for(auto sheet_node : doc.child("workbook").child("sheets").children("sheet"))
+    {
+        std::string id = sheet_node.attribute("r:id").as_string();
+        std::string name = sheet_node.attribute("name").as_string();
+        sheets.push_back(std::make_pair(id, name));
+    }
+    return sheets;
+}
+
+document_properties reader::read_properties_core(const std::string &xml_string)
+{
+    document_properties props;
+    pugi::xml_document doc;
+    doc.load(xml_string.c_str());
+    auto root_node = doc.child("cp:coreProperties");
+    props.creator = root_node.child("dc:creator").text().as_string();
+    return props;
+}
+
 std::string reader::read_dimension(const std::string &xml_string)
 {
     pugi::xml_document doc;
diff --git a/source/workbook.cpp b/source/workbook.cpp
index c8cb603a..e5d2157c 100644
--- a/source/workbook.cpp
+++ b/source/workbook.cpp
@@ -313,6 +313,11 @@ bool workbook::load(const std::string &filename)
     }
     
     auto workbook_relationships = reader::read_relationships(f.get_file_contents("xl/_rels/workbook.xml.rels"));
+
+    for(auto relationship : workbook_relationships)
+    {
+        create_relationship(relationship.first, relationship.second.first, relationship.second.second);
+    }
     
     pugi::xml_document doc;
     doc.load(f.get_file_contents("xl/workbook.xml").c_str());
@@ -334,15 +339,33 @@ bool workbook::load(const std::string &filename)
     
     for(auto sheet_node : sheets_node.children("sheet"))
     {
-        auto relation_id = sheet_node.attribute("r:id").as_string();
+        std::string relation_id = sheet_node.attribute("r:id").as_string();
         auto ws = create_sheet(sheet_node.attribute("name").as_string());
         std::string sheet_filename("xl/");
-        sheet_filename += workbook_relationships[relation_id].first;
+        sheet_filename += get_relationship(relation_id).get_target_uri();
         xlnt::reader::read_worksheet(ws, f.get_file_contents(sheet_filename).c_str(), shared_strings);
     }
 
     return true;
 }
+
+void workbook::create_relationship(const std::string &id, const std::string &target, const std::string &type)
+{
+    d_->relationships_.push_back(relationship(type, id, target));
+}
+
+relationship workbook::get_relationship(const std::string &id) const
+{
+    for(auto &rel : d_->relationships_)
+    {
+        if(rel.get_id() == id)
+        {
+            return rel;
+        }
+    }
+
+    throw std::runtime_error("");
+}
     
 int workbook::get_base_year() const
 {
@@ -497,11 +520,17 @@ bool workbook::save(const std::string &filename)
             {"/xl/styles.xml", "application/vnd.openxmlformats-officedocument.spreadsheetml.styles+xml"},
             {"/xl/workbook.xml", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"},
             {"/docProps/app.xml", "application/vnd.openxmlformats-officedocument.extended-properties+xml"},
-            {"/xl/worksheets/sheet1.xml", "application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"},
             {"/docProps/core.xml", "application/vnd.openxmlformats-package.core-properties+xml"},
             {"/xl/theme/theme1.xml", "application/vnd.openxmlformats-officedocument.theme+xml"}
         }
     };
+
+    int ws_index = 1;
+    for(auto ws : *this)
+    {
+        auto sheet_filename = "/xl/worksheets/sheet" + std::to_string(ws_index++) + ".xml";
+        content_types.second[sheet_filename] = "application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml";
+    }
     
     f.set_file_contents("[Content_Types].xml", writer::write_content_types(content_types));
     
@@ -511,38 +540,35 @@ bool workbook::save(const std::string &filename)
         {"rId2", {"docProps/core.xml", "http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties"}},
         {"rId1", {"xl/workbook.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"}}
     };
+
     f.set_file_contents("_rels/.rels", writer::write_relationships(root_rels));
     
     std::vector<std::pair<std::string, std::pair<std::string, std::string>>> workbook_rels =
     {
-        {"rId1", {"worksheets/sheet1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"}},
+        {"rId1", {"sharedStrings.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings"}},
         {"rId2", {"styles.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"}},
         {"rId3", {"theme/theme1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme"}}
     };
-    f.set_file_contents("xl/_rels/workbook.xml.rels", writer::write_relationships(workbook_rels));
-    
-    pugi::xml_document doc;
-    auto root_node = doc.append_child("workbook");
-    root_node.append_attribute("xmlns").set_value("http://schemas.openxmlformats.org/spreadsheetml/2006/main");
-    root_node.append_attribute("xmlns:r").set_value("http://schemas.openxmlformats.org/officeDocument/2006/relationships");
-    auto sheets_node = root_node.append_child("sheets");
-    
-    int i = 0;
+
+    ws_index = 2;
+    for(auto ws : *this)
+    {
+        auto sheet_filename = "worksheets/sheet" + std::to_string(ws_index++) + ".xml";
+        workbook_rels.push_back({"rId" + std::to_string(ws_index + 1), {sheet_filename, "http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"}});
+    }
+
+    f.set_file_contents("xl/_rels/workbook.xml.rels", writer::write_relationships(workbook_rels));
+    
+    int i = 0;
+
     for(auto ws : *this)
     {
-        auto sheet_node = sheets_node.append_child("sheet");
-        sheet_node.append_attribute("name").set_value(ws.get_title().c_str());
-        sheet_node.append_attribute("sheetId").set_value(std::to_string(i + 1).c_str());
-        sheet_node.append_attribute("r:id").set_value((std::string("rId") + std::to_string(i + 1)).c_str());
         std::string filename = "xl/worksheets/sheet";
         f.set_file_contents(filename + std::to_string(i + 1) + ".xml", xlnt::writer::write_worksheet(ws));
         i++;
     }
-    
-    std::stringstream ss;
-    doc.save(ss);
-    
-    f.set_file_contents("xl/workbook.xml", ss.str());
+
+    f.set_file_contents("xl/workbook.xml", writer::write_workbook(*this));
 
     return true;
 }
diff --git a/source/writer.cpp b/source/writer.cpp
index 6b6bbc94..204bd108 100644
--- a/source/writer.cpp
+++ b/source/writer.cpp
@@ -35,15 +35,31 @@ std::string writer::write_string_table(const std::vector<std::string> &string_ta
     return ss.str();
 }
 
-std::string writer::write_workbook_rels(const workbook &/*wb*/)
+std::string writer::write_properties_core(const document_properties &/*prop*/)
 {
-    static const std::vector<std::pair<std::string, std::pair<std::string, std::string>>> rels =
+    return "";
+}
+
+std::string writer::write_properties_app(const workbook &/*wb*/)
+{
+    return "";
+}
+
+std::string writer::write_workbook_rels(const workbook &wb)
+{
+    std::vector<std::pair<std::string, std::pair<std::string, std::string>>> rels =
     {
-        {"rId1", {"worksheets/sheet1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"}},
-        {"rId2", {"sharedStrings.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings"}},
-        {"rId3", {"styles.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"}},
-        {"rId4", {"theme/theme1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme"}}
+        {"rId1", {"sharedStrings.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings"}},
+        {"rId2", {"styles.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"}},
+        {"rId3", {"theme/theme1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme"}}
     };
+
+    int i = 0;
+    for(auto worksheet : wb)
+    {
+        rels.push_back({"rId" + std::to_string(i + 4), {"worksheets/sheet1.xml", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"}});
+        i++;
+    }
     
     return write_relationships(rels);
 }
diff --git a/source/zip_file.cpp b/source/zip_file.cpp
index 7a7c790c..f87533e7 100644
--- a/source/zip_file.cpp
+++ b/source/zip_file.cpp
@@ -57,9 +57,9 @@ zip_file::~zip_file()
     change_state(state::closed);
 }
 
-std::string zip_file::get_file_contents(const std::string &filename)
+std::string zip_file::get_file_contents(const std::string &filename) const
 {
-    return files_[filename];
+    return files_.at(filename);
 }
 
 void zip_file::set_file_contents(const std::string &filename, const std::string &contents)
diff --git a/tests/runner-autogen.cpp b/tests/runner-autogen.cpp
index 6ea03b74..09c7e416 100644
--- a/tests/runner-autogen.cpp
+++ b/tests/runner-autogen.cpp
@@ -565,41 +565,41 @@ public:
 static test_props suite_test_props;
 
 static CxxTest::List Tests_test_props = { 0, 0 };
-CxxTest::StaticSuiteDescription suiteDescription_test_props( "../../tests/test_props.hpp", 8, "test_props", suite_test_props, Tests_test_props );
+CxxTest::StaticSuiteDescription suiteDescription_test_props( "../../tests/test_props.hpp", 10, "test_props", suite_test_props, Tests_test_props );
 
 static class TestDescription_suite_test_props_test_read_properties_core : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_read_properties_core() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 25, "test_read_properties_core" ) {}
+ TestDescription_suite_test_props_test_read_properties_core() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 13, "test_read_properties_core" ) {}
  void runTest() { suite_test_props.test_read_properties_core(); }
 } testDescription_suite_test_props_test_read_properties_core;
 
 static class TestDescription_suite_test_props_test_read_sheets_titles : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_read_sheets_titles() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 36, "test_read_sheets_titles" ) {}
+ TestDescription_suite_test_props_test_read_sheets_titles() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 30, "test_read_sheets_titles" ) {}
  void runTest() { suite_test_props.test_read_sheets_titles(); }
 } testDescription_suite_test_props_test_read_sheets_titles;
 
 static class TestDescription_suite_test_props_test_read_properties_core2 : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_read_properties_core2() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 57, "test_read_properties_core2" ) {}
+ TestDescription_suite_test_props_test_read_properties_core2() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 42, "test_read_properties_core2" ) {}
  void runTest() { suite_test_props.test_read_properties_core2(); }
 } testDescription_suite_test_props_test_read_properties_core2;
 
 static class TestDescription_suite_test_props_test_read_sheets_titles2 : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_read_sheets_titles2() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 64, "test_read_sheets_titles2" ) {}
+ TestDescription_suite_test_props_test_read_sheets_titles2() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 50, "test_read_sheets_titles2" ) {}
  void runTest() { suite_test_props.test_read_sheets_titles2(); }
 } testDescription_suite_test_props_test_read_sheets_titles2;
 
 static class TestDescription_suite_test_props_test_write_properties_core : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_write_properties_core() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 72, "test_write_properties_core" ) {}
+ TestDescription_suite_test_props_test_write_properties_core() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 62, "test_write_properties_core" ) {}
  void runTest() { suite_test_props.test_write_properties_core(); }
 } testDescription_suite_test_props_test_write_properties_core;
 
 static class TestDescription_suite_test_props_test_write_properties_app : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_props_test_write_properties_app() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 84, "test_write_properties_app" ) {}
+ TestDescription_suite_test_props_test_write_properties_app() : CxxTest::RealTestDescription( Tests_test_props, suiteDescription_test_props, 73, "test_write_properties_app" ) {}
  void runTest() { suite_test_props.test_write_properties_app(); }
 } testDescription_suite_test_props_test_write_properties_app;
 
diff --git a/tests/test_props.hpp b/tests/test_props.hpp
index f267c503..c28ea839 100644
--- a/tests/test_props.hpp
+++ b/tests/test_props.hpp
@@ -4,91 +4,78 @@
 #include <cxxtest/TestSuite.h>
 
 #include <xlnt/xlnt.hpp>
+#include "helpers/path_helper.hpp"
+#include "helpers/helper.hpp"
 
 class test_props : public CxxTest::TestSuite
 {
 public:
-    class TestReaderProps
-    {
-        void setup_class(int cls)
-        {
-            //cls.genuine_filename = os.path.join(DATADIR, "genuine", "empty.xlsx");
-            //cls.archive = ZipFile(cls.genuine_filename, "r", ZIP_DEFLATED);
-        }
-
-        void teardown_class(int cls)
-        {
-            //cls.archive.close();
-        }
-    };
-
     void test_read_properties_core()
     {
-        //content = archive.read(ARC_CORE)
-        //    prop = read_properties_core(content)
-        //    TS_ASSERT_EQUALS(prop.creator, "*.*")
-        //    eacute = chr(233)
-        //    TS_ASSERT_EQUALS(prop.last_modified_by, "Aur" + eacute + "lien Camp" + eacute + "as")
-        //    TS_ASSERT_EQUALS(prop.created, datetime(2010, 4, 9, 20, 43, 12))
-        //    TS_ASSERT_EQUALS(prop.modified, datetime(2011, 2, 9, 13, 49, 32))
+        xlnt::zip_file archive(PathHelper::GetDataDirectory() + "/genuine/empty.xlsx", xlnt::file_mode::open);
+        auto content = archive.get_file_contents("docProps/core.xml");
+        auto prop = xlnt::reader::read_properties_core(content);
+        TS_ASSERT_EQUALS(prop.creator, "*.*");
+        unsigned char eacute = 233;
+        std::string modified_by = "Aur";
+        modified_by.append(1, eacute);
+        modified_by += "lien Camp";
+        modified_by.append(1, eacute);
+        modified_by += "as";
+        TS_ASSERT_EQUALS(prop.last_modified_by, modified_by);
+        TS_ASSERT_EQUALS(prop.created, xlnt::datetime(2010, 4, 9, 20, 43, 12));
+        TS_ASSERT_EQUALS(prop.modified, xlnt::datetime(2011, 2, 9, 13, 49, 32));
     }
 
     void test_read_sheets_titles()
     {
-        //content = archive.read(ARC_WORKBOOK);
-        //sheet_titles = read_sheets_titles(content);
-        //TS_ASSERT_EQUALS(sheet_titles, \
-        //    ["Sheet1 - Text", "Sheet2 - Numbers", "Sheet3 - Formulas", "Sheet4 - Dates"]);
+        xlnt::zip_file archive(PathHelper::GetDataDirectory() + "/genuine/empty.xlsx", xlnt::file_mode::open);
+        auto content = archive.get_file_contents("docProps/core.xml");
+        std::vector<std::string> expected_titles = {"Sheet1 - Text", "Sheet2 - Numbers", "Sheet3 - Formulas", "Sheet4 - Dates"};
+        int i = 0;
+        for(auto sheet : xlnt::reader::read_sheets(archive))
+        {
+            TS_ASSERT_EQUALS(sheet.second, expected_titles[i++]);
+        }
     }
 
-         // Just tests that the correct date / time format is returned from LibreOffice saved version
+    void test_read_properties_core2()
+    {
+        xlnt::zip_file archive(PathHelper::GetDataDirectory() + "/genuine/empty_libre.xlsx", xlnt::file_mode::open);
+        auto content = archive.get_file_contents("docProps/core.xml");
+        auto prop = xlnt::reader::read_properties_core(content);
+        TS_ASSERT_EQUALS(prop.excel_base_date, xlnt::calendar::windows_1900);
+    }
 
-        void setup_class(int cls)
+    void test_read_sheets_titles2()
+    {
+        xlnt::zip_file archive(PathHelper::GetDataDirectory() + "/genuine/empty_libre.xlsx", xlnt::file_mode::open);
+        auto content = archive.get_file_contents("docProps/core.xml");
+        std::vector<std::string> expected_titles = {"Sheet1 - Text", "Sheet2 - Numbers", "Sheet3 - Formulas", "Sheet4 - Dates"};
+        int i = 0;
+        for(auto sheet : xlnt::reader::read_sheets(archive))
         {
-            //cls.genuine_filename = os.path.join(DATADIR, "genuine", "empty_libre.xlsx")
-            //    cls.archive = ZipFile(cls.genuine_filename, "r", ZIP_DEFLATED)
-        }
-
-        void teardown_class(int cls)
-        {
-            //cls.archive.close()
-        }
-
-        void test_read_properties_core2()
-        {
-        //    content = archive.read(ARC_CORE)
-        //        prop = read_properties_core(content)
-        //        TS_ASSERT_EQUALS(prop.excel_base_date, CALENDAR_WINDOWS_1900)
-        }
-
-        void test_read_sheets_titles2()
-        {
-            //content = archive.read(ARC_WORKBOOK)
-            //    sheet_titles = read_sheets_titles(content)
-            //    TS_ASSERT_EQUALS(sheet_titles, \
-            //    ["Sheet1 - Text", "Sheet2 - Numbers", "Sheet3 - Formulas", "Sheet4 - Dates"])
+            TS_ASSERT_EQUALS(sheet.second, expected_titles[i++]);
         }
+    }
 
     void test_write_properties_core()
     {
-        //prop.creator = "TEST_USER"
-        //    prop.last_modified_by = "SOMEBODY"
-        //    prop.created = datetime(2010, 4, 1, 20, 30, 00)
-        //    prop.modified = datetime(2010, 4, 5, 14, 5, 30)
-        //    content = write_properties_core(prop)
-        //    assert_equals_file_content(
-        //    os.path.join(DATADIR, "writer", "expected", "core.xml"),
-        //    content)
+        xlnt::document_properties prop;
+        prop.creator = "TEST_USER";
+        prop.last_modified_by = "SOMEBODY";
+        prop.created = xlnt::datetime(2010, 4, 1, 20, 30, 00);
+        prop.modified = xlnt::datetime(2010, 4, 5, 14, 5, 30);
+        auto content = xlnt::writer::write_properties_core(prop);
+        TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/core.xml", content));
     }
 
     void test_write_properties_app()
     {
-        //wb = Workbook()
-        //    wb.create_sheet()
-        //    wb.create_sheet()
-        //    content = write_properties_app(wb)
-        //    assert_equals_file_content(
-        //    os.path.join(DATADIR, "writer", "expected", "app.xml"),
-        //    content)
+        xlnt::workbook wb;
+        wb.create_sheet();
+        wb.create_sheet();
+        auto content = xlnt::writer::write_properties_app(wb);
+        TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/app.xml", content));
     }
 };
diff --git a/tests/test_read.hpp b/tests/test_read.hpp
index ee5e55a7..94c68110 100644
--- a/tests/test_read.hpp
+++ b/tests/test_read.hpp
@@ -38,7 +38,7 @@ public:
     void test_read_standard_workbook_from_fileobj()
     {
         auto path = PathHelper::GetDataDirectory() + "/genuine/empty.xlsx";
-        std::ifstream fo(path);
+        std::ifstream fo(path, std::ios::binary);
         xlnt::workbook wb;
         wb.load(fo);
     }