Hewings, Martin, author
Cambridge University Press , 2004
Buku Teks
Shau, Wing Chan, author
Stanford University Press, 1946
Buku Referensi
Wichman, K., author
New York, David Mckay Company
Buku Referensi
Breul, Karl, author
Boston D.C. Heath 1936
Buku Referensi
Baker, Ann, author
Cambridge University Press, 1982
Buku Teks