@inproceedings{POPL-1992-Tofte,
	author        = "Mads Tofte",
	booktitle     = "{Conference Record of the 19th Annual Symposium on Principles of Programming Languages}",
	doi           = "10.1145/143165.143206",
	editor        = "Ravi Sethi",
	isbn          = "0-89791-453-8",
	pages         = "189--199",
	publisher     = "{ACM Press}",
	title         = "{Principal Signatures for Higher-Order Program Modules}",
	year          = 1992,
}