OCLC Research Searchable
One of the arms of OCLC focuses on research. It is “devoted exclusively to the challenges facing libraries in a rapidly changing information technology environment.” Their repository, which includes works produced, sponsored, or submitted by OCLC Research, reaches back to 1970.
You are now able to search this repository by keyword, author, year, subject, and title. There is an advanced search as well as a browse function. The search interface is a prototype and they are asking for comments, so if you use it, let them know what you thought!
[FYI – I work for an OCLC network.]