@inproceedings{OOPSLA-1993-LiskovW,
	author        = "Barbara Liskov and Jeannette M. Wing",
	booktitle     = "{Proceedings of the Eighth Conference on Object-Oriented Programming, Systems, Languages and Applications}",
	doi           = "10.1145/165854.165863",
	editor        = "Timlynn Babitsky and Jim Salmons",
	isbn          = "0-89791-587-9",
	pages         = "16--28",
	publisher     = "{ACM}",
	title         = "{Specifications and Their Use in Defining Subtypes}",
	year          = 1993,
}