Rotavirus associated diarrhoea during infancy in the city of s. Luis (ma), brazil: a two-year longitudinal study - Stewien, Klaus Eberhard; Cunha, L C F; Alvim, C; Reis Filho, S A; Alvim, M A B; Brandao, A A P; Neiva, M N R (Revista do Instituto de Medicina Tropical de Sao Paulo, 1991)