@inproceedings{POPL-1995-HofmannP,
	author        = "Martin Hofmann and Benjamin C. Pierce",
	booktitle     = "{Conference Record of the 22nd Symposium on Principles of Programming Languages}",
	doi           = "10.1145/199448.199482",
	editor        = "Ron K. Cytron and Peter Lee",
	isbn          = "0-89791-692-1",
	pages         = "186--197",
	publisher     = "{ACM Press}",
	title         = "{Positive Subtyping}",
	year          = 1995,
}