Gates, N L Serologic survey of prevalence of ovine progressive pneumonia in Idaho range sheep. [electronic resource] - Journal of the American Veterinary Medical Association Dec 1978 - 1575-7 p. digital Publication Type: Journal Article ISSN: 0003-1488 Subjects--Topical Terms: AnimalsAntibodies, Viral--analysisIdahoImmunodiffusionPneumonia, Progressive Interstitial, of Sheep--epidemiologySheepVisna-maedi virus--immunology