@inproceedings{SIGIR-2001-ZhaiL,
	author        = "ChengXiang Zhai and John D. Lafferty",
	booktitle     = "{Proceedings of the 24th International ACM SIGIR Conference on Research and Development in Information Retrieval}",
	doi           = "10.1145/383952.384019",
	isbn          = "1-58113-331-6",
	pages         = "334--342",
	publisher     = "{ACM}",
	title         = "{A Study of Smoothing Methods for Language Models Applied to Ad Hoc Information Retrieval}",
	year          = 2001,
}