The Anal Cancer Foundation
http://www.analcancerfoundation.org/American Cancer Society
http://www.cancer.org/cancer/cancercauses/othercarcinogens/infectiousagents/hpv/indexCenters for Disease Control and Prevention (CDC)
http://www.cdc.gov/std/healthcomm/hc-hpv.htmPublic Health Agency of Canada
http://www.phac-aspc.gc.ca/std-mts/hpv-vph/hpv-vph-vaccine-eng.php