@booklet {parkes01h,
	title = {Achieving Budget-Balance with Vickrey-Based Payment Schemes in Combinatorial Exchanges},
	year = {2001},
	note = {Updated, March 2002},
	publisher = {IBM Research Report RC 22218},
	url = {http://econcs.seas.harvard.edu/files/econcs/files/combexch.pdf},
	author = {David C. Parkes and Jayant R. Kalagnanam and Marta Eso}
}
