As per our agreement with WorldCat, we are not allowed to store data we retrieve from worldcat in restbase any longer than 72 hours.

We have two options

1. Prevent all requests from being stored longer than 72 hours
2. Check if "WorldCat" appears in the "source" Array, and if so, prevent this from being stored in restbase. If the string does not appear, store the citation.

I am not sure how difficult either option would be.