From #109

We could automatically generate a key on upload, and then allow the users to edit the key if they want. A common choice for a key is the first author's last name plus the publication year, e.g. hammerbacher1999. If there's a key collision just append a, b, c, etc. If we don't have metadata just use untitled plus 1, 2, 3, etc.

Looking at the 9 PDFs I have been using locally, Grobid only captures a date for 2 of them. I think these PDFs came from arxiv, so maybe that's part of the reason? Regardless, we'll need to improve this with the medium-term task of canonicalize references against some database.