schema:citation : "A citation or reference to another creative work, such as another publication, web page, scholarly article, etc."

Proposal :

schema:citedBy : "Indicates a creative work, such as another publication, web page or scholarly article that cites this work"
Domain : schema:CreativeWork
Range : Text or CreativeWork
InverseOf : schema:citation.

Optionally, for consistent naming, a better name for schema:citation would be "schema:cites".

Use cases for schema:citedBy : legislation being cited in judgments, scholarly articles cited in other articles, blog post backlinks, etc.