@book{89778,
	author = {Zubiri Apalategui, Xavier},
	title = {Sobre la esencia},
	publisher = {Sociedad de Estudios y Publicaciones},
	year = {1963.},
	series = {Estudios filosóficos / Xavier Zubiri},
	address = {Madrid [Spain]},
	edition = {3a ed.}
}