@book{34,
	author = {Orellana Manrique, Oswaldo and Universidad Nacional Mayor de San Marcos},
	title = {Desarrollo cognitivo},
	publisher = {UNMSM, Facultad de Educación},
	year = {1999},
	address = {Lima},
	edition = {2a ed},
	note = {Incluye glosario de términos}
}