Chan Stephen; Moore Cerwyn
Sage, 2006
Buku Teks
Buss, Claude Albert
Mamillan, 1955
Buku Teks
Griffith, Ernest S.
New York University press, 1956
Buku Teks
Griffith, Ernest S.
New York University press, 1952
Buku Teks
Toynbee, Arnold J.
Oxford University Press, 1956
Buku Teks