Restoring an older version of a cross-doc source

I have a doc called “Student Master” that contains all the demographic info of my school’s students. I then use cross-doc to sync that master data into a variety of other docs.

Today I realized that I made some big errors while messing around with the Student Master doc, and so I restored an older version that did not contain those screwups.

How can I get my cross-doc links to reference the restored version rather than the screwed up version of Student Master?