Yee, James, author
Dastan Books , 2006
Buku Teks
Zumwalt, Admiral Elmo
Macmillan Publishing Company, 1986
Buku Teks
Hare, Bill, author
[American Management Association, ], 2004
eBooks
Lockwood, Charles A., author
Grunberg, 1956
Buku Teks
Montgomery, David, author
Cambridge University Press, 1979
Buku Teks