Are there any openly-accessible databases for searching journal article metadata? I’m particularly looking for abstracts, citation data, and subjects/tags/fields-of-study information. I’m looking for something like Sciverse Scopus (but not just for Elsevier) or CiteSeerX, but not just for CS.
I’m not just looking for open access journals, and would like to at least cover however many thousand major journals there are across all fields of study.
There are several different potential sources of information. I don't think any are completely comprehensive and few would count as strict "open data": apart from Open Access titles, licensing is likely to vary between publishers.
Having said that you could look at some of the following sources:
Essentially there are publisher specific APIs, subject aggregators, and a few cross-industry services. CrossRef as a DOI registry are a good starting point.
Its worth noting that given a DOI, you can now get structured metadata about the article using content negotiation, i.e. a simple HTTP request. This includes all CrossRef and DataCite DOIs. More information, including examples.
http://libguides.mit.edu/apis gives a very nice list of APIs for scholarly resources, here is snapshot of the page in case it disappears:
There are, but each system has a different scope, and so only collect up articles that they're interested in. For instance:
If you're asking about standards for releasing the metadata ... it's not really set up for individuals to search on, but OAI-PMH (Protocol for Metadata Harvesting) allows for bulk downloading of metadata from repositories that support the standard.
The February memo from OSTP on public access to (US) federally funded research specifically mentions in section 3:
c) Ensure full public access to publications’ metadata without charge upon first publication in a data format that ensures interoperability with current and future search technology. Where possible, the metadata should provide a link to the location where the full text and associated supplemental materials will be made available after the embargo period;
... but we don't yet know how it will be implemented. It might that each agency will keep a registry or repository of the articles developed by their funding, or there might be a centralized one for all agencies, or it might prompt journals to start supporting OAI-PMH to make it easier for Google Scholar and others to aggregate it all in once place.
Citation data at least can be found in OpenCitations.
