Seth, Michael J., author
Littlefield, 2011
Buku Teks
edited by Fritz Stern
Meredian Books, 1959
Buku Teks
edited by Fritz Stern
Merridian Book, 1972
Buku Teks
editor, Robert Aldrich, Garry Wotherspoon.
Roudledge, 2001
Buku Referensi
Toynbee, Arnold J., author
Oxford University Press, 1956
Buku Teks