@book{26336,
	author = {Iafrancesco Villegas, Giovanni Marcelo},
	title = {Aportes a la didáctica constructivista de las ciencias naturales /},
	publisher = {Libros y Libres,},
	year = {1997},
	address = {Santa Fé De Bogotá :},
	edition = {1 ed.}
}