Finding Links to other files

How do I find a file link? Usually, when opening a file with a link to another there is a "view link" button however I have files which open with "update" "don't update" and "help" buttons and I need to find & delete the link because I'm not aware of linkages in a couple of these files! Using the "trace dependants" does not reveal which file (or sheet within the same file for that matter). Any suggestions? Leon