Encyclopedia of ethics : volume III
Lawrence C. Becker, Charlotte B. Becker, editors
Routledge, 2001
 Buku Referensi
Hastings, James
Encyclopedia of religion and ethics; Volume VIII
T&T Clark, 1980
 Buku Referensi
Hastings, James
Encyclopedia of religion and ethics; Volume IX
T&T Clark, 1980
 Buku Referensi
Hastings, James
Encyclopedia of religion and ethics; Volume XI
T&T Clark, 1980
 Buku Referensi
Hastings, James
Encyclopedia of religion and ethics; Volume XII
T&T Clark, 1980
 Buku Referensi