Stewien, Klaus Eberhard, Edison Luíz Durigon, Hatune Tanaka, Alfredo Elias Gilio, and Evandro Roberto Baldacci. 1991. “ Occurrence of Human Astrovirus in S. Paulo City, Brazil ”. Revista De Saúde Pública 25 (2): 157-58. https://doi.org/10.1590/S0034-89101991000200011.