Passmore, John, author
Gerald Duckworth, 1957
Buku Teks
Passmore, John, author
Penguin Books, 1972
Buku Teks
Williams, Melanie, author
Cavendish Publishing Limited, 2002
Buku Teks
Briere, S.J., author
George Allen and Unwin , 1956
Buku Teks
edited by John K. Ryan
The Catholic University of America Press, 1963
Buku Teks