@inproceedings{ECIR-2004-AmatiCR,
	author        = "Giambattista Amati and Claudio Carpineto and Giovanni Romano",
	booktitle     = "{Proceedings of the 26th European Conference on Information Retrieval Research: Advances in Information Retrieval}",
	doi           = "10.1007/978-3-540-24752-4_10",
	isbn          = "3-540-21382-1",
	pages         = "127--137",
	publisher     = "{Springer International Publishing}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Query Difficulty, Robustness, and Selective Application of Query Expansion}",
	volume        = 2997,
	year          = 2004,
}