@article{Weerdt13geb,
	author          = {Mathijs M. de Weerdt and Paul Harrenstein and Vincent Conitzer },
	title           = {Strategy-Proof Contract Auctions and the Role of Ties},
	journal         = {Games and Economic Behavior},
	year            = {2014},
	volume          = {86},
	pages           = {405-420},
	issn            = {0899-8256},
	url             = {http://www.sciencedirect.com/science/article/pii/S0899825613001309},
	project         = {NGI},
	group           = {ALG}
}