Abdala, Nadia, Nathan B. Hansen, Olga V. Toussova, Tatiana V. Krasnoselskikh, Andrei P. Kozlov, and Robert Heimer. "Age at first alcoholic drink as predictor of current HIV sexual risk behaviors among a sample of injection drug users (IDUs) and non-IDUs who are sexual partners of IDUs, in St. Petersburg, Russia." AIDS and behavior 16, no. 6 (2012): 1597-604.