@inproceedings{POPL-2000-Walker,
	author        = "David Walker",
	booktitle     = "{Proceedings of the 27th Symposium on Principles of Programming Languages}",
	doi           = "10.1145/325694.325728",
	editor        = "Mark N. Wegman and Thomas W. Reps",
	isbn          = "1-58113-125-9",
	pages         = "254--267",
	publisher     = "{ACM}",
	title         = "{A Type System for Expressive Security Policies}",
	year          = 2000,
}