Winstanley Erin L, Gust Steven W, Strathdee Steffanie A
Johns Hopkins Bloomberg School of Public Health, Department of Health Policy and Management, 624 N. Broadway. Baltimore, MD 21211, USA.
Drug Alcohol Depend. 2006 Apr;82 Suppl 1:S1-5. doi: 10.1016/s0376-8716(06)80001-3.