Welch, Jack, author
Harper Business, 2005
Buku Teks
Krause, Donald G., author
American Management Association;, 2008
eBooks
Podolinsky, Michael A, author
McGraw-Hill, 2011
Buku Teks
Asiapac Books, 2002
Buku Teks
Cohen, William A., author
[American Management Association, ], 2004
eBooks