J.B. Metzler, 1995
Buku Referensi
Ross, Harris
Greenwood Press, 1987
Buku Referensi
Kolker, Robert, author
Oxford University Press, 2000
Buku Teks
DeNitto, Dennis
Harper & Row Pub., 1985
Buku Teks
Anderson, Joseph L., author
Charles E. Tuttle, 1965
Buku Teks