Molecular characterization of astrovirus in stool samples from children in São Paulo, Brazil - Resque, Hugo Reis; Munford, Veridiana; Castilho, Juliana Galera; Schmich, Herika; Caruzo, Thabata Alessandra Ramos; Rácz, Maria Lucia Barbosa de Oliveira (Memórias do Instituto Oswaldo Cruz, 2007)