@inproceedings{STOC-1986-HalpernV,
	author        = "Joseph Y. Halpern and Moshe Y. Vardi",
	booktitle     = "{Proceedings of the 18th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/12130.12161",
	isbn          = "0-89791-193-8",
	pages         = "304--315",
	publisher     = "{ACM}",
	title         = "{The Complexity of Reasoning about Knowledge and Time: Extended Abstract}",
	year          = 1986,
}