@article {IIIA-2007-1297, title = {Savings in combinatorial auctions through transformation relationships}, journal = {Trading Agent Design and Analysis \& Agent Mediated Electronic Commerce VIII. Lecture Notes in Computer Science}, volume = {4452}, year = {2007}, pages = {17-30}, author = {Andrea Giovannucci and Juan A. Rodr{\'\i}guez-Aguilar and Jes{\'u}s Cerquides} }