small changes

Author: mongoKart

source/reference.txt

@@ -16,7 +16,7 @@ Reference
    Quick Reference </reference/quick-reference>
    Compatibility </reference/compatibility>
    Upgrade </reference/upgrade>
-   Previous Versions </reference/previous-versions>
+   Versions 2.0 to 2.18 </reference/previous-versions>
 
 Previous Versions
 -----------------

source/reference/previous-versions.txt

@@ -1,8 +1,8 @@
 .. _csharp-previous-versions:
 
-=================
-Previous Versions
-=================
+====================
+Versions 2.0 to 2.18
+====================
 
 The following links direct you to documentation for previous versions of the
 driver.

source/reference/upgrade.txt

@@ -21,8 +21,8 @@ Upgrade Driver Versions
    :titlesonly:
    :maxdepth: 1
 
-   Version 2.x </upgrade/v2>
-   Version 3.0 </upgrade/v3>
+   Version 2.x </reference/upgrade/v2>
+   Version 3.0 </reference/upgrade/v3>
 
 Overview
 --------