@inproceedings{ICALP-1988-VaziraniY,
	author        = "Vijay V. Vazirani and Mihalis Yannakakis",
	booktitle     = "{Proceedings of the 15th International Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-19488-6_149",
	isbn          = "3-540-19488-6",
	pages         = "667--681",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Pfaffian Orientations, 0/1 Permanents, and Even Cycles in Directed Graphs}",
	volume        = 317,
	year          = 1988,
}