Haidinger, Timothy P.
John Wiley & Sons, 1975
Buku Teks
McGraw-Hill, INC, 1992
Buku Teks
Corrigan, Timothy
Scott, Foresman and Company, 1989
Buku Teks
Zofi, Yael, author
Amacom, 2012
Buku Teks
Reis, Matthew, author
American Management Association, 2010
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