Walker, Richard
De Agostini, 1996
Buku Teks
Sudjic, Deyan
Mitchell Beazley, 1986
Buku Referensi
Paulson, Edward
Prenada Media, 2003
Buku Teks
Solovic, Susan Wilson, 1958-
Amacom, 2012
Buku Teks
Segal, Lloyd M., 1948-
American Management Association, 2007
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