Risk of infection with hiv among health professional of the hospital of clinics medical faculty of ribeirao preto-university of sao paulo (hcfmrp) - brazil - Machado, A. A.; Costa, J C; Gir, Elucir; Moriya, Tokico Murakawa; Figueiredo, J F C (International Conference on Aids Biopsychosocial Aspects of Hiv Infection, 1991)