edited by Keith Lehrer and Ernest Sosa
Westview Press, 1991
Buku Teks
Indian Committee for Cultural Freedom, 1999
Buku Teks
edited by Andrew Blowers, Chris Hammett and Philip Sarre
Hutchinson Educational in association with the Open University Press, 1974
Buku Teks
Outhwaite, William
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Buku Teks
Friedmann, Wolfgang, 1907-1972
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Buku Teks