Q-Sensei – Search Engine for Scholarly Sources
http://lambda.qsensei.com/

Q-Sensei Scholarly Search Engine searches and browses through their collection of the following sources: a) ArXiv; b) Ingenta Connect; c) Library of Congress; d) PubMed; and e) RePEc. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog. This will be added to Academic and Scholar Search Engines and Sources white paper.