@book{69621,
	author = {Rapkin, Minnie K. and Howitt, Lillian C.},
	title = {Enseñanza de la aritmética elemental},
	publisher = {Unión Tipográfica Editorial Hispano Americana},
	year = {c1968.},
	series = {Manual UTEHA breve},
	address = {México},
	note = {Translation of Teaching the third "R."}
}