@inproceedings{CIKM-2008-HauffMB,
	author        = "Claudia Hauff and Vanessa Murdock and Ricardo A. Baeza-Yates",
	booktitle     = "{Proceedings of the 17th ACM International Conference on Information and Knowledge Management}",
	doi           = "10.1145/1458082.1458142",
	isbn          = "978-1-59593-991-3",
	pages         = "439--448",
	publisher     = "{ACM}",
	title         = "{Improved query difficulty prediction for the web}",
	year          = 2008,
}