Pepall, Lynne, author
Thomson , 2005
Buku Teks
Thompson, Arthur A., 1940-, author
Prentice-Hall, 1989
Buku Teks
Waldman, Don E., author
Pearson, 2007
Buku Teks
Drucker, Peter F. (Peter Ferdinand), 1909-2005, author
Harper & Brothers, 1954
Buku Teks
Manajemen Usahawan Indonesia, XXXII (04) April 2003: 21-27, 2003
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