@book{6826,
	author = {Lesser, Milton S. and Contin, Agustín},
	title = {Enseñanza efectiva de las ciencias},
	publisher = {Hispano Americana},
	year = {1968},
	series = {Manual Uthea breve. Educación},
	address = {México, D.F.},
	edition = {1ª ed.}
}