Skidmore, Rex A. (Rex Austin), author
Prentice-Hall, 1994
Buku Teks
Dubois, Brenda, 1949-, author
Allyn and Boston, 1992
Buku Teks
Rhodhes, Margaret L., author
Routledge and Kegan Paul, 1986
Buku Teks
Seden, Janet, author
Open University Press, 2005
Buku Teks
UNSW
UNSW, 2000
Buku Teks