Office 2007 - Referencing sources in Word

"Microsoft Word inserts cross-references as fields. If an item you referred to in a cross-reference isn't correct, you need to manually update the cross-reference fields by selecting a specific cross-reference or the entire document and then pressing F9. Another option is to reference bookmarks.

Here are some resources you could check:

Troubleshoot cross-references
Inserting Cross References in Word 2007
Change a cross-reference"