The following has been added to the Zotero Group for Ancient World Open Bibliographies. Content formerly at the Bibliographies Page at this site is now being hosted at the Ancient World Open Bibliographies Wiki.
Classical Philosophy:
Presocratics: Bibliography
http://www.philosophy.gr/presocratics/bibliography.htm
Giannis Stamatellos, Centre for Neoplatonic Virtue Ethics, University of Copenhagen.
Copyrighted 2006, which is presumably the last update.
A short bibliography, mostly in English.
Ancient World Open Bibliographies 