Prevalence of hiv and risk-taking behaviors among disadvantaged youth in sao paulo - brazil - Massad, Eduardo; Burattini, Marcelo Nascimento; Azevedo Neto, Raymundo Soares de; Strazza, Leila; Menezes, R X; Carvalho, H. B; Medeiros, M; Petrescu, C S; Almeida, L N B; Castrignano, S B; Meneghin, Paolo; Netzert, E (International Conference on Aids, 1996)