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Buku Teks
Kutner, Peter B.
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Buku Teks
Lynne Reiner, 1988
Buku Teks
Wolf, Charles
Princeton University press, 1960
Buku Teks
edited by Jacqueline A. Kalley, Elna Schoeman, Marlene Burger
University of South Africa, 2005
Buku Teks