HIV testing frequency among men who have sex with men attending sexually transmitted disease clinics: implications for HIV prevention and surveillance.
Helms DJ, Weinstock HS, Mahle KC, Bernstein KT, Furness BW, Kent CK, Rietmeijer CA, Shahkolahi AM, Hughes JP, Golden MR. HIV testing frequency among men who have sex with men attending sexually transmitted disease clinics: implications for HIV prevention and surveillance. J Acquir Immune Defic Syndr. 2009 Mar 01; 50(3):320-6.