Beauchamp, Tom L.
Oxford University Press, 2013
Buku Teks
Mappes, Thomas A.
McGraw-Hill, 1986
Buku Teks
Veatch, Robert M.
Oxford University Press, 2015
Buku Teks
Garrett, Thomas M.
Prentice-Hall, 2001
Buku Teks
edited by James M. Humber and Robert F. Almeder
Humana Press, 1995
Buku Teks