@inproceedings{CIKM-2008-MasudaT,
	author        = "Katsuya Masuda and Jun'ichi Tsujii",
	booktitle     = "{Proceedings of the 17th ACM International Conference on Information and Knowledge Management}",
	doi           = "10.1145/1458082.1458273",
	isbn          = "978-1-59593-991-3",
	pages         = "1349--1350",
	publisher     = "{ACM}",
	title         = "{Nested region algebra extended with variables for tag-annotated text search}",
	year          = 2008,
}