Mcgilvray, James, author
Polity, 2014
Buku Teks
Kim, Jaegwon, author
Westview Press, 2006
Buku Teks
Maslin, K.T.
Polity Press, 2007
Buku Teks
Robinson, Ian
Cambridge University Press, 1975
Buku Teks
Brian Beakley; Peter Ludlow
MIT Press , 2006
Buku Teks