Creswell, Clifford J., author
ITB Press, 1982
Buku Teks
Christie, David
UNSW Press, 1997
Buku Teks
Cairncross, Sandy, author
John Wiley & Sons, 1993
Buku Teks
Morel, Francois, 1944-, author
John Wiley & Sons, 1993
Buku Teks
Fassett, Norman C.
University of Wisconsin Press, 1985
Buku Referensi