Davis, Rowland H., author
Oxrord University Press, 2003
Buku Teks
Whitelam, Keith W
Raoutledge , 1996
Buku Teks
Coleman, Janet, author
Blackwell Publishers, Ltd, 2000
Buku Teks
Ilyon, author
Yonsei University Press, 2004
Buku Teks
Botsford, George Willis
Macmillan, 1939
Buku Teks