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
ed. by Saxe Commins & Robert N. Linscott.
Random House , 1947
Buku Teks SO
Schlivek, Louis B.
Doubleday, 1965
Buku Teks SO
Burke, Lance B.
[American Management Association;, ], 2004
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