@book{119781,
	author = {Hasenjaeger, Gisbert},
	title = {Conceptos y problemas de la lógica moderna},
	publisher = {Editorial Labor},
	year = {[1968]},
	address = {Barcelona},
	note = {Translation of : Einführung in die Grunbegriffe und Probleme der modernen Logik.}
}