WEB
PAGES
Farabee, M J. Excretory System. 1992. 23 Feb. 2006
<http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookEXCRET.html>.Lubey, . Human Excretory System. 1999. 23 Feb. 2006 <http://www.borg.com/~lubehawk/hexcrsys.htm>.
Gregory, Michael . Excretory System. 23 Feb. 2006 <http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Excretory%20System/excretor.htm>.
BOOKS
Silverstein, Alvin, Virginia
Silverstein, and Robert Silverstein. The Excretory System. Brookfield:
Twenty- First Century Books, 1994.
The Human Body. New York: DK, 1995.
The Human Body. : Time- Life, 1997.
The Human Body. New York: DK, 1995.
The Human Body. : Time- Life, 1997.