Shilling, James D.
South-Western, 2002
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Kau, James B.
McGraw-Hill, 1985
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Sigit Harnowo
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2014
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Maisel, Sherman J.
McGraw-Hill, 1976
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Fisher, Ernest McKinley
Macmillan, 1923
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