ed. by Saxe Commins & Robert N. Linscott.
Random House , 1947
Buku Teks
Robert M. Hutchins, Mortimer J. Adler, editors in chief
Encyclopaedia Britannica, Inc., 1963
Buku Referensi
Robert M. Hutchins, Mortimer J. Adler, editors in chief
Encyclopaedia Britannica, Inc., 1963
Buku Referensi
Schlivek, Louis B.
Doubleday, 1965
Buku Teks
Burke, Lance B.
[American Management Association;, ], 2004
eBooks