1. Doing Quantitative Research in the Social Sciences. An Integrated Approach to Research Design, Measurement and Statistics;Black,1999
2. Brazil, C., 1995. Presentation at the 6th International Conference on the Reduction of Drug-Related Harm. Florence, Italy.
3. The sharing of injecting equipment and the AIDS epidemic in New York City: the first decade. Needle sharing among intravenous drug abusers: national and international perspectives;Des Jarlais;NIDA,1988
4. Grund, Jean-Paul C., 1993. Drug Use as Social Ritual: Functionality, Symbolism and Determinants of Self Regulation. Ch.X1 1: The sharing of needles and other injecting paraphermalta: an ethnographic analysis.