McVey, Ruth Thomas, author
Cornell university, 1962, 1957.
Buku Teks
Weigh, Ken Shen
The Coomercial Press , 1928
Buku Teks
Dallin, David J.
Yale University Press, 1949
Buku Teks
Lensen, George Alexander, author
Sophia University, 1970
Buku Teks
Vishwanathan, Savitri, author
Diplomatic Press, 1973
Buku Teks