Messenger, William E., author
Prentice-Hall, 1989
Buku Teks
Dean, Howard H.
Prentice-Hall, 1962
Buku Teks
Iacone, Salvatore J., author
Carrer Press, 2003
Buku Teks
Brannan, Bob, author
McGraw-Hill , 2003
Buku Teks
Wilson, Kevin, 1958- , author
American Management Association;, 2010
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