Hughes, Rebecca, author
Pearson Education, 2002
Buku Teks
Astrid S. Susanto, author
Binacipta, 1988
Buku Teks
Astrid S. Susanto, author
Bina Cipta, 1977
Buku Teks
[publisher not identified], [date of publication not identified]
Naskah
Withers, Bill, author
American Management Association, 2003
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