King-Hall, Stephen
Methuen & Co. Ltd., 1924
Buku Teks
Timperlake, Edward
Regnery Publishing, 1999
Buku Teks
Liu, Shia-Ling, author
Kuang Lu Publishing , 1988
Buku Teks
Kiernan, E.V.G., author
Cambridge University Press, 1939
Buku Teks
UNESCO, 1980
Buku Teks