Hurtsthouse, Rosalind, author
Routledge, 2000
Buku Teks
Lewis, Barry, author
Wadsworth and Cengage Learning, 2013
Buku Teks
Pojman, Louis P., author
Wadsworth and Cengage Learning, 2012
Buku Teks
Schinzinger, Roland, author
McGraw-Hill, 2000
Buku Teks
Lee, Steven P., author
Cambridge University Press, 2012
Buku Teks