Ferrell, O.C.
Cengage Learning, 2015
Buku Teks SO
Devettere, Raymond J.
Georgetown University Press, 1995
Buku Teks
Veatch, Robert M.
Oxford University Press, 2015
Buku Teks SO
Veatch, Robert M.
Oxford University Press, 2008
Buku Teks SO
Du Mas, Mark M.
MdM Books, 2010
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