Skubik, Daniel W.
Peter Lang , 1990
Buku Teks
Raz, Joseph, author
Oxford Univesity Press, 2009
Buku Teks
Windolph, F. Lyman
Princeton University press, 1951
Buku Teks
Finnis, John, author
Oxford Univesity Press, 2011
Buku Teks
Anderson, Owen J., author
Cambridge University Press, 2012
Buku Teks