@book{107121,
	author = {Schain, Robert L. and Polner, Murray.},
	title = {Obtención y empleo de medios de enseñanza económicos y gratuitos /},
	publisher = {Unión Tipográfica Editorial Hispano Americana,},
	year = {c1968.},
	address = {México :},
	edition = {1. ed. en español.},
	note = {Translation of Where to get and how to use free and inexpensive teaching aids.}
}