No abstract available
MeSH terms
-
Cross-Sectional Studies
-
HIV Antibodies / blood
-
HIV Infections / epidemiology
-
Homosexuality, Male*
-
Humans
-
London
-
Male
-
Piperazines / administration & dosage*
-
Purines
-
Risk-Taking
-
Sexual Behavior*
-
Sildenafil Citrate
-
Sulfones
-
Surveys and Questionnaires
Substances
-
HIV Antibodies
-
Piperazines
-
Purines
-
Sulfones
-
Sildenafil Citrate