Nicholson, John, author
BBC Books , 1992
Buku Teks
Bennie, Michael, author
Elex Media Komputindo, 1996
Buku Teks
White, Roderick, author
McGraw-Hill, 1980
Buku Teks
White, Roderick, author
McGraw-Hill, 1993
Buku Teks
Allen, William Richard, 1924-, author
American Management Association, 1993
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