@inproceedings{CIKM-2011-KarimzadehganZ,
	author        = "Maryam Karimzadehgan and ChengXiang Zhai",
	booktitle     = "{Proceedings of the 20th ACM International Conference on Information and Knowledge Management}",
	doi           = "10.1145/2063576.2063586",
	isbn          = "978-1-4503-0717-8",
	pages         = "27--36",
	publisher     = "{ACM}",
	title         = "{Improving retrieval accuracy of difficult queries through generalizing negative document language models}",
	year          = 2011,
}