@book{3193,
	author = {Duffy, Tim.},
	title = {Cuatro Herramientas de Software-plus: MS Dos, Word Perfect, Lotus 1,2,3 y dBAse III plus.},
	publisher = {Grupo Editorial Iberoamérica},
	year = {1990},
	address = {México},
	edition = {1ª }
}