@book{31142,
	author = {Ferreiro, Emilia and Teberosky, Ana},
	title = {<Los> Sistemas de Escritura en el Desarrollo del Niño /},
	publisher = {Siglo Veintiuno Editores,},
	year = {2007.},
	series = {Educación},
	address = {Madrid :},
	edition = {13.}
}