Brown, Larry
Algonquin Books of Chapel Hill, 1996
Buku Teks
Throssell, ric
Mandarin Australia, 1990
Buku Teks
Meredith, George
J.M. Dent & Sons, 1935
Buku Teks
Zumwalt, Admiral Elmo
Macmillan Publishing Company, 1986
Buku Teks
Flaum, Sandra A.
American Management Association, 2006
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