Brennan, Joseph Gerard, author
Harper & Row, 1967
Buku Teks
edited by John Cottingham
Blackwell, 2008
Buku Teks
Warburton, Nigel, 1962-
Routledge, 1995
Buku Teks
Rachels, James, 1941-2003, author
McGraw-Hill, 2012
Buku Teks
Reader in Philosophy, University of The Panjab, 1965
Buku Teks