@book{33571,
	author = {Walter, Robert. and Villar Borda, Luis,},
	title = {La doctrina del derecho de Hans Kelsen /},
	publisher = {Universidad Externado de Bogotá,},
	year = {2001.},
	series = {Serie de teoria juridica y filosofia del derecho ;},
	address = {Bogotá :}
}