One reason I was able to build BioNames is because a significant fraction of the taxonomic literature for animals is now online, either due to the efforts of the Biodiversity Heritage Library, digital archives, commercial publishers, or individual institutions and scientific societies. However there are still big gaps in literature availability.

I've been using ISSN's (International Standard Serial Number) to uniquely identify journals, both to generate article identifiers, and as a parameter to send to CrossRef's OpenURL resolver. Recently I've come across journals that change their ISSN, which has fairly catastrophic effects on my lookup tools.