Below you'll find links to some other sites around the Internet that I've found helpful in doing the eRA research during the development of the Tool.
LSU Working Bibliography on Online Reverse Auction Bidding
Emiliani and Stec Reverse Auction Research Page
Primer on Combinatorial and Integer Optimization
Procurement Strategy Council
Center for Advanced Purchasing Studies (CAPS) Research
CombineNet, Inc. - the leader in combinatorial optimization applications for supply chain management
Primer on Multi-Attribute Reverse Auctions
http://csdl2.computer.org/comp/proceedings/hicss/2004/2056/07/205670165b.pdf