diff --git a/markdown.go b/markdown.go
index 6bb0a90..d2dc321 100644
--- a/markdown.go
+++ b/markdown.go
@@ -20,6 +20,7 @@ package blackfriday
 
 import (
 	"bytes"
+	"fmt"
 	"strings"
 	"unicode/utf8"
 )
@@ -516,6 +517,11 @@ type reference struct {
 	text     []byte
 }
 
+func (r *reference) String() string {
+	return fmt.Sprintf("{link: %q, title: %q, text: %q, noteId: %d, hasBlock: %v}",
+		r.link, r.title, r.text, r.noteId, r.hasBlock)
+}
+
 // Check whether or not data starts with a reference link.
 // If so, it is parsed and stored in the list of references
 // (in the render struct).