Pizzol, M.D. Ravazzolo, A.P. Goncalves, I.P.D. Hotzel, I. Fernandes, J.C.T. Moojen, V. Maedi-visna: evidencia de ovinos infectados no Rio Grande do Sul, Brasil, 1987-1989 Subjects--Topical Terms: OVINOVIRUSDIAGNOSTICORIO GRANDE DO SUL