edited by Abdel M. Agami
Random House, 1989
Buku Referensi
Westminter, Maryland Random Haouse Inc. 1989,
Buku Teks
Kohler, Eric L., author
Prentice-Hall, 1957
Buku Referensi
edited by W.A. Paton
Ronald Press, 1955
Buku Teks
Stivens, Dal, 1911-1997
Brittanicus Liber, 1951
Buku Teks