Genetic variations among PRRSV strains isolated in Italy and in Russia V.G. Andreyev, A.V. Scherbakov, V.A. Pylnov, A.A. Gusev, P. Cordioli and G. Sala Vet. Res., 31 1 (2000) 89-90 DOI: 10.1051/vetres:2000003