@inproceedings{SIGIR-2010-CarmelY,
	author        = "David Carmel and Elad Yom-Tov",
	booktitle     = "{Proceedings of the 33rd International ACM SIGIR Conference on Research and Development in Information Retrieval}",
	doi           = "10.1145/1835449.1835683",
	isbn          = "978-1-4503-0153-4",
	pages         = "911",
	publisher     = "{ACM}",
	title         = "{Estimating the query difficulty for information retrieval}",
	year          = 2010,
}