Mackenizie, John
Illinois: Dow Jones-Irwin, 1989
Buku Teks
Moss, Stephen R.
Prentice-Hall, 2001
Buku Teks
Cope, Mick
Financial Times Prentice Hall, 2003
Buku Teks
Diggs, Steve
Golden Books Centre, 1990
Buku Teks
Levinson, Nan
[American Management Association;, ], 2000
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