David Kempe Mahyar Salek Cristopher Moore Frugal and Truthful Auctions for Vertex Covers, Flows and Cuts. 745-754 2010 FOCS http://doi.ieeecomputersociety.org/10.1109/FOCS.2010.76 conf/focs/2010 db/conf/focs/focs2010.html#KempeSM10