@inproceedings{POPL-1973-LewisR,
	author        = "Clayton H. Lewis and Barry K. Rosen",
	booktitle     = "{Conference Record of the First Symposium on Principles of Programming Languages}",
	doi           = "10.1145/512927.512939",
	editor        = "Patrick C. Fischer and Jeffrey D. Ullman",
	pages         = "125--138",
	publisher     = "{ACM Press}",
	title         = "{Recursively Defined Data Types}",
	year          = 1973,
}