Long, A. A., author
Claaarendon Press, 2004
Buku Teks
Chesters, Sarah Davey
Sense, 2012
eBooks
Chen, Liu-Fu, author
Philosophical Library, 1948
Buku Teks
Toynbee, Arnold J., author
Oxford University Press, 1976
Buku Teks
George, Richard T. de
Regents Press of Kansas, 1980
Buku Referensi