Dainow, Sheila, author
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Buku Teks
Famularo, J.J.
McGraw-Hill, 1961
Buku Teks
Adair, John, author
Pan Books , 1988
Buku Teks
Bishop, Graham, author
Routledge, 2005
Buku Teks
Charney, Cyril, author
American Management Association, 2006
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