@inproceedings{ITiCSE-1999-Levin,
	author        = "Martin H. Levin",
	booktitle     = "{Proceedings of the Fourth Conference on Innovation and Technology in Computer Science Education}",
	doi           = "10.1145/305786.305868",
	isbn          = "1-58113-087-2",
	pages         = "79--83",
	publisher     = "{ACM}",
	title         = "{Use of a soundcard in teaching audio frequency and analog modem communications}",
	year          = 1999,
}