@book{125520,
	author = {Gesell, Arnold Lucius and Ilg, Frances Lillian},
	title = {El niño de 9 y 10 años},
	publisher = {Editorial Paidos},
	year = {c[1967, c1963].},
	series = {Biblioteca del educador contemporáneo},
	address = {Buenos Aires},
	edition = {4. ed. rev.}
}