edited by R. Lewis and ED Tagg
Blackwell, 1987
Buku Teks
edited by Alfred M. Bork
Pergamon Press, 1980
Buku Teks
Patton, William E., author
South-Western, 1992
Buku Teks
Houston, Brant, author
St. Martin Press, 1996
Buku Referensi
Hoit, Marc, author
Prentice-Hall, 1995
Buku Teks