diff --git a/include/xlnt/utils/datetime.hpp b/include/xlnt/utils/datetime.hpp
index 654ded09..9cbb6aef 100644
--- a/include/xlnt/utils/datetime.hpp
+++ b/include/xlnt/utils/datetime.hpp
@@ -54,7 +54,7 @@ struct XLNT_CLASS datetime
 
     datetime(int year_, int month_, int day_, int hour_ = 0, int minute_ = 0, int second_ = 0, int microsecond_ = 0);
 
-    std::string to_string(calendar base_date) const;
+    std::string to_string() const;
     long double to_number(calendar base_date) const;
     bool operator==(const datetime &comparand) const;
 
diff --git a/include/xlnt/worksheet/page_margins.hpp b/include/xlnt/worksheet/page_margins.hpp
index fddba423..b61a8248 100644
--- a/include/xlnt/worksheet/page_margins.hpp
+++ b/include/xlnt/worksheet/page_margins.hpp
@@ -56,13 +56,14 @@ public:
     void set_footer(double footer);
 
 private:
-    bool default_;
-    double top_;
-    double left_;
-    double bottom_;
-    double right_;
-    double header_;
-    double footer_;
+    bool default_ = true;
+
+    double top_ = 1;
+    double left_ = 0.75;
+    double bottom_ = 1;
+    double right_ = 0.75;
+    double header_ = 0.5;
+    double footer_ = 0.5;
 };
 
 } // namespace xlnt
diff --git a/include/xlnt/worksheet/range.hpp b/include/xlnt/worksheet/range.hpp
index f764bc48..2fb6d2a1 100644
--- a/include/xlnt/worksheet/range.hpp
+++ b/include/xlnt/worksheet/range.hpp
@@ -76,6 +76,12 @@ public:
     std::size_t length() const;
 
     bool contains(const cell_reference &ref);
+    
+    cell_vector front();
+    const cell_vector front() const;
+
+    cell_vector back();
+    const cell_vector back() const;
 
     iterator begin();
     iterator end();
diff --git a/source/detail/worksheet_impl.hpp b/source/detail/worksheet_impl.hpp
index 35a5f3b7..6d3968cd 100644
--- a/source/detail/worksheet_impl.hpp
+++ b/source/detail/worksheet_impl.hpp
@@ -44,14 +44,10 @@ namespace detail {
 struct worksheet_impl
 {
     worksheet_impl(workbook *parent_workbook, const std::string &title)
-        : parent_(parent_workbook), title_(title), comment_count_(0)
+        : parent_(parent_workbook),
+          title_(title),
+          comment_count_(0)
     {
-        page_margins_.set_left(0.75);
-        page_margins_.set_right(0.75);
-        page_margins_.set_top(1);
-        page_margins_.set_bottom(1);
-        page_margins_.set_header(0.5);
-        page_margins_.set_footer(0.5);
     }
 
     worksheet_impl(const worksheet_impl &other)
diff --git a/source/styles/tests/test_stylesheet.hpp b/source/styles/tests/test_stylesheet.hpp
index 96717d93..95341916 100644
--- a/source/styles/tests/test_stylesheet.hpp
+++ b/source/styles/tests/test_stylesheet.hpp
@@ -41,6 +41,20 @@ public:
         TS_ASSERT_EQUALS(e.get_stylesheet().number_formats.size(), 0);
     }
 
+    void test_add_existing_style()
+    {
+        xlnt::workbook wb;
+        xlnt::excel_serializer e(wb);
+
+        TS_ASSERT_EQUALS(e.get_stylesheet().styles.size(), 1);
+
+        auto &s = wb.create_style("test");
+        TS_ASSERT_EQUALS(e.get_stylesheet().styles.size(), 2);
+
+        wb.add_style(s);
+        TS_ASSERT_EQUALS(e.get_stylesheet().styles.size(), 2);
+    }
+
 /*
     void _test_unprotected_cell()
     {
diff --git a/source/utils/datetime.cpp b/source/utils/datetime.cpp
index ca0786e6..90415cde 100644
--- a/source/utils/datetime.cpp
+++ b/source/utils/datetime.cpp
@@ -65,7 +65,7 @@ long double datetime::to_number(calendar base_date) const
     return date(year, month, day).to_number(base_date) + time(hour, minute, second, microsecond).to_number();
 }
 
-std::string datetime::to_string(xlnt::calendar /*base_date*/) const
+std::string datetime::to_string() const
 {
     return std::to_string(year) + "/" + std::to_string(month) + "/" + std::to_string(day) + " " + std::to_string(hour) +
            ":" + std::to_string(minute) + ":" + std::to_string(second) + ":" + std::to_string(microsecond);
diff --git a/source/utils/tests/test_datetime.hpp b/source/utils/tests/test_datetime.hpp
index 5519f391..fd7dc488 100644
--- a/source/utils/tests/test_datetime.hpp
+++ b/source/utils/tests/test_datetime.hpp
@@ -16,6 +16,12 @@ public:
         TS_ASSERT_EQUALS(t.second, 45);
     }
 
+    void test_to_string()
+    {
+        xlnt::datetime dt(2016, 7, 16, 9, 11, 32, 999999);
+        TS_ASSERT_EQUALS(dt.to_string(), "2016/7/16 9:11:32:999999");
+    }
+
     void test_carry()
     {
         // We want a time that rolls over to the next second, minute, and hour
diff --git a/source/workbook/tests/test_workbook.hpp b/source/workbook/tests/test_workbook.hpp
index 0da32e71..0ff54d0f 100644
--- a/source/workbook/tests/test_workbook.hpp
+++ b/source/workbook/tests/test_workbook.hpp
@@ -260,5 +260,14 @@ public:
         TS_ASSERT_EQUALS(iter, copy);
     }
     
-    // void test_add_invalid_worksheet_class_instance() {} not needed in c++
+    void test_manifest()
+    {
+        xlnt::default_type d;
+        TS_ASSERT(d.get_content_type().empty());
+        TS_ASSERT(d.get_extension().empty());
+
+        xlnt::override_type o;
+        TS_ASSERT(o.get_content_type().empty());
+        TS_ASSERT(o.get_part_name().empty());
+    }
 };
diff --git a/source/worksheet/page_margins.cpp b/source/worksheet/page_margins.cpp
index 28cb5339..0bc9e6a4 100644
--- a/source/worksheet/page_margins.cpp
+++ b/source/worksheet/page_margins.cpp
@@ -25,7 +25,7 @@
 
 namespace xlnt {
 
-page_margins::page_margins() : default_(true), top_(0), left_(0), bottom_(0), right_(0), header_(0), footer_(0)
+page_margins::page_margins()
 {
 }
 
diff --git a/source/worksheet/range.cpp b/source/worksheet/range.cpp
index 8b405b0f..d3daa415 100644
--- a/source/worksheet/range.cpp
+++ b/source/worksheet/range.cpp
@@ -94,7 +94,27 @@ bool range::contains(const cell_reference &ref)
 
 cell range::get_cell(const cell_reference &ref)
 {
-    return (*this)[ref.get_row()][ref.get_column().index];
+    return (*this)[ref.get_row() - 1][ref.get_column().index - 1];
+}
+
+cell_vector range::front()
+{
+    return *begin();
+}
+
+const cell_vector range::front() const
+{
+    return *cbegin();
+}
+
+cell_vector range::back()
+{
+    return *(--end());
+}
+
+const cell_vector range::back() const
+{
+    return *(--cend());
 }
 
 range::iterator range::begin()
diff --git a/source/worksheet/tests/test_worksheet.hpp b/source/worksheet/tests/test_worksheet.hpp
index 3319f5f9..1d9b2092 100644
--- a/source/worksheet/tests/test_worksheet.hpp
+++ b/source/worksheet/tests/test_worksheet.hpp
@@ -999,8 +999,12 @@ public:
     {
         xlnt::workbook wb;
         auto ws = wb.get_active_sheet();
-        ws.get_page_margins();
-        //TODO: uhh... this isn't a test
+        auto &margins = ws.get_page_margins();
+
+        TS_ASSERT(margins.is_default());
+
+        margins.set_bottom(1);
+        TS_ASSERT(!margins.is_default());
     }
 
     void test_to_string()
@@ -1090,6 +1094,9 @@ public:
         ws1.create_named_range("rangey", "A2:A2");
         TS_ASSERT_EQUALS(ws1[std::string("rangey")], ws1.get_range("A2:A2"));
         TS_ASSERT_EQUALS(ws1[std::string("A2:A2")], ws1.get_range("A2:A2"));
+        TS_ASSERT_DIFFERS(ws1[std::string("rangey")], ws1.get_range("A2:A3"));
+
+        TS_ASSERT_EQUALS(ws1[std::string("rangey")].get_cell("A1"), ws1.get_cell("A2"));
     }
 
     void test_reserve()