Literature updating: Multiple pmids are possible

[keelinm]

We currently only support a single pmid for a single article. However if the article existed in preprint form and later in peer-reviewed form it can actually have 2 different pmids, and it is not guaranteed in any way that we store the one that links to the peer-reviewed version.
Example is Roth22 which has pmid 36156419 (journal medical image analysis) and also pmid 34100010 (preprint) and in our bib file we store the preprint pmid which is not really ideal.