Staub, Ervin
Cambridge, 2003
Buku Teks
Staub, Ervin
university press, 2003
Buku Teks
Yardan, John L.
The Council for Research in Values and Philosophy , 2001
Buku Teks
Kimbali, Charles
Mizan Media Utama (MMU), 2003
Buku Teks
Cambridge University Press , 2004
Buku Teks