Katz V., G. Lentz, R. Lobo, D. Gershenson. Comprehensive Gynecology. 5th ed. Mosby Elsevier, 2007. Accessed on Ovember 23, 2010 from http://www.mdconsult.com.
Schorge, J., J. Schaeffer, L. Hoalvorson, B. Hoffmen, K. Bradshaw, F. Cunningham. Williams Gynecology. 1st ed. The Mcgraw Hill Companies, Inc. 2008.
ACOG Practice Bulletin: Human Papillomairus, Number 61, April 2005.