@inproceedings{CIKM-2012-MacdonaldSO,
	author        = "Craig Macdonald and Rodrygo L. T. Santos and Iadh Ounis",
	booktitle     = "{Proceedings of the 21st ACM International Conference on Information and Knowledge Management}",
	doi           = "10.1145/2396761.2398691",
	isbn          = "978-1-4503-1156-4",
	pages         = "2559--2562",
	publisher     = "{ACM}",
	title         = "{On the usefulness of query features for learning to rank}",
	year          = 2012,
}