@inproceedings{SIGIR-2009-Voorhees,
	author        = "Ellen M. Voorhees",
	booktitle     = "{Proceedings of the 32nd International ACM SIGIR Conference on Research and Development in Information Retrieval}",
	doi           = "10.1145/1571941.1572138",
	isbn          = "978-1-60558-483-6",
	pages         = "806--807",
	publisher     = "{ACM}",
	title         = "{Topic set size redux}",
	year          = 2009,
}