@inproceedings{CFLP-1987-HarperMT,
	author        = "Robert Harper and Robin Milner and Mads Tofte",
	booktitle     = "{Proceedings of the Second International Joint Conference on Theory and Practice of Software Development, Volume 2: Colloquium on Functional and Logic Programming and Specifications}",
	doi           = "10.1007/BFb0014988",
	isbn          = "3-540-17611-X",
	pages         = "308--319",
	publisher     = "{Springer}",
	title         = "{A Type Discipline for Program Modules}",
	year          = 1987,
}