@INPROCEEDINGS{PenVen06, AUTHOR = {P. Penna and C. Ventre}, TITLE = {The Algorithmic Structure of Group Strategyproof Budget-Balanced Cost-Sharing Mechanisms}, BOOKTITLE = {23rd Annual Symposium on Theoretical Aspects of Computer Science (STACS)}, YEAR = {2006}, volume = {3884}, series = {LNCS}, pages = {337-348} }