High genetic diversity of hepatitis E virus in swine in São Paulo State, Brazil oleh A. Cortez, C.S. Metorima, S.A.T. Miyagi, A.O. Sousa, A.V. Peyser, A.M.M.G. Castro, F.A. Baldisseri Jr, A.F. Souza Filho, P.E. Brandão, M.B. Heinemann