Cohen, Akiba A., author
Sage Publications, 1987
Buku Teks
Moffatt, Thomas L.
Harper & Row , 1979
Buku Teks
Popovich, Igor S., author
Abdi Tandur, 1996
Buku Teks
McGraw-Hill/Glencoe, 2003
Buku Teks
Beshara, Tony, 1948- , author
American Management Association, 2008
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