@inproceedings{CL-2000-BroersenWM,
	author        = "Jan M. Broersen and Roel Wieringa and John-Jules Ch. Meyer",
	booktitle     = "{Proceedings of the First International Conference on Computational Logic}",
	doi           = "10.1007/3-540-44957-4_61",
	isbn          = "3-540-67797-6",
	pages         = "912--925",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{A Semantics for Persistency in Propositional Dynamic Logic}",
	volume        = 1861,
	year          = 2000,
}