Gyarmathy, Anna V., Nan Li, Karin E. Tobin, Irving F. Hoffman, Nikolai Sokolov, Julia Levchenko, Julia Batluk, Andrei A. Kozlov, Andrei P. Kozlov, and Carl A. Latkin. "Correlates of unsafe equipment sharing among injecting drug users in St. Petersburg, Russia." European addiction research 15, no. 3 (2009): 163-70.