Staub, Ervin
university press, 2003
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Yardan, John L.
The Council for Research in Values and Philosophy , 2001
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William Wardoyo
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2016
UI - Skripsi (Membership)
Kimbali, Charles
Mizan Media Utama (MMU), 2003
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Kramer, Matthew H.
Oxford University Press, 2014
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