edited by Joel Feinberg, Hyman Gross
Wadsworth, 1977
Buku Teks
Pojman, Louis P., author
Thomson Wadsworth, 2006
Buku Teks
Fieser, James, author
Oxford University Press, 2005
Buku Teks
edited by Ralph E. Pumphrey and Muriel W. Pumphrey
Columbia University Press, 1961
Buku Teks
Stumpf, Samuel Enoch, 1918-1998, author
McGraw-Hill, 1971
Buku Teks