@inproceedings{DAC-1978-DavidV,
	acmid         = "803110",
	author        = "Bertrand T. David and G. Vitry",
	booktitle     = "{Proceedings of the 15th Design Automation Conference}",
	pages         = "321--325",
	publisher     = "{ACM}",
	title         = "{SIGMA-CAD: Some new concepts in design of general purpose CAD systems}",
	year          = 1978,
}