1. European Centre for the Epidemiological Monitoring of AIDS. AIDS surveillance in Europe No. 37. Paris: Hôpital Saint-Maurice, 1993.
2. Anderson R. AIDS: trends, prediction, controversy. Nature 1993;363:393?394.
3. Rapiti E, Perucci CA, Sangalli M, Abeni DD, Carboni A, Miceli M. Reliability of exposure definition in surveillance systems of HIV infection. [Abstract PO-C27-3247.3.] IX International Conference on AIDS, Berlin F.R. Germany, June 6?11, 1993.
4. European Centre for the Epidemiological Monitoring of AIDS. AIDS surveillance in Europe No. 38. Paris: Hôpital Saint-Maurice, 1993.
5. Centers for Disease Control. Update on acquired immunodeficiency syndrome (AIDS) ? United States. MMWR, 1982;31:507?514.