Unfortunately, the PubMed link via the View button is converted to a View Snapshot after attachment of a file. Once that has happened there's no easy way to call up the PubMed page of a publication. That's no good with PubMed being the most frequently used repository for life scientists.

Zotero should have a little drop down menu similar to the Locate button that allows us to call up the PubMed page even after we made a Snapshot.