@inproceedings{LICS-1999-GradelW,
	author        = "Erich Grädel and Igor Walukiewicz",
	booktitle     = "{Proceedings of the 14th Annual IEEE Symposium on Logic in Computer Science}",
	doi           = "10.1109/LICS.1999.782585",
	isbn          = "0-7695-0158-3",
	pages         = "45--54",
	publisher     = "{IEEE Computer Society}",
	title         = "{Guarded Fixed Point Logic}",
	year          = 1999,
}