@inproceedings{CIKM-2009-AchananuparpYC,
	author        = "Palakorn Achananuparp and Christopher C. Yang and Xin Chen",
	booktitle     = "{Proceedings of the 18th ACM International Conference on Information and Knowledge Management}",
	doi           = "10.1145/1645953.1646203",
	isbn          = "978-1-60558-512-3",
	pages         = "1681--1684",
	publisher     = "{ACM}",
	title         = "{Using negative voting to diversify answers in non-factoid question answering}",
	year          = 2009,
}