@book{227458,
	author = {Popham, Estelle L. and De Muñoz, Beatriz},
	title = {Un sistema de enseñanza-aprendizaje para educación comercial},
	publisher = {McGraw-Hill Latinoamericana},
	year = {1980.},
	address = {Bogotá},
	note = {Includes index.}
}