Diamond, 2001
Buku Referensi
Fang, Yuqing, author
Beijing daxue Chubanshe, 2000
Buku Teks
Wright, W., author
University Press, 1951
Buku Teks
Whitney, William Dwight, author
Harvard University Press, 1941
Buku Teks
Douglas, Dan, author
Cambridge University Press, 2000
Buku Teks