@inproceedings{JCDL-2006-PetrasLB,
	author        = "Vivien Petras and Ray R. Larson and Michael K. Buckland",
	booktitle     = "{Proceedings of the Sixth Joint Conference on Digital Libraries}",
	doi           = "10.1145/1141753.1141782",
	isbn          = "1-59593-354-9",
	pages         = "151--160",
	publisher     = "{ACM}",
	title         = "{Time period directories: a metadata infrastructure for placing events in temporal and geographic context}",
	year          = 2006,
}