@inproceedings{POPL-1977-Hehner,
	author        = "Eric C. R. Hehner",
	booktitle     = "{Conference Record of the Fourth Symposium on Principles of Programming Languages}",
	cdrom         = "POPL/00001443.PDF",
	doi           = "10.1145/512950.512969",
	editor        = "Robert M. Graham and Michael A. Harrison and Ravi Sethi",
	pages         = "201--205",
	publisher     = "{ACM}",
	title         = "{Structuring}",
	year          = 1977,
}