edited by Robert C. Scharff
Blackwell, 2005
Buku Teks
edited by Robert C. Scharff, Val Dusek
Wiley Blackwell, 2014
Buku Teks
edited by John Cottingham
Blackwell, 2008
Buku Teks
Pojman, Louis P.
English : 6th ed., International ed., 2012
Buku Teks
Cambridge University Press , 2008
Buku Teks