Associations between substance use and sexual risk among very young men who have sex with men

David D. Celentano, Linda A. Valleroy, Frangiscos Sifakis, Duncan A. Mackellar, John Hylton, Hanne Thiede, Willi Mcfarland, Douglas A. Shehan, Susan R. Stoyanoff, Marlene Lalota, Beryl A. Koblin, Mitchell H. Katz, Lucia V. Torian