Occurrence of Sarcocystis spp. in opossums (Didelphis aurita and Didelphis albiventris) in regions of the State of São Paulo, Brazil - Casagrande, Renata Assis; Cesar, Marina de Oliveira; Pena, Hilda Fátima de Jesus; Zwarg, Ticiana; Teixeira, Rodrigo Hidalgo Friciello; Nunes, Adauto Luis Veloso; Neves, Dafne do Valle Dutra de Andrade; Gomes, Marcelo; Quagglia Neto, Fausto; Milanello, Liliane; Fontenelle, José Heizteman; Matushima, Eliana Reiko (Brazilian Journal of Veterinary Research and Animal Science, 2009)