West view press, 1989
Buku Teks
Turri, John, author
John Wiley & Sons, 2014
Buku Teks
edited by Ben Kotzee
Wiley-Blackwell, 2014
Buku Teks
Rescher, Nicholas, author
State University of New York Press, 2003
Buku Teks
Audi, Robert, author
Routledge, 2011
Buku Teks