@inproceedings{SIGIR-2009-He,
	author        = "Jiyin He",
	booktitle     = "{Proceedings of the 32nd International ACM SIGIR Conference on Research and Development in Information Retrieval}",
	doi           = "10.1145/1571941.1572171",
	isbn          = "978-1-60558-483-6",
	pages         = "850",
	publisher     = "{ACM}",
	title         = "{Topic structure for information retrieval}",
	year          = 2009,
}