Collier's encyclopedia, 20 volumes with bibliography and index - Collier, firm publishers, New York (New York, New York : Collier, 1958)
Volume 1, 2,3 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20
Collier's year book./ New York, P.F/ Collier, 1953--La Biblioteca contiene años: 1952-53, 1955, 1957
Keywords: ENCICLOPEDIAS Y DICCIONARIOS