1. E.C. Burgess, J. Ossa, M. Yuill, Avian Dis. 23, 940–949 (1979)
2. Y.X. Huang, J. South China Agric. Univ. 1, 1–12 (1959)
3. C.M. Fauquet, M.A. Mayo, J. Maniloff, U. Desselberger, L.A. Ball, Virus Taxonomy: Eighth Report of the International Committee on Taxonomy of Viruses (Elsevier Academic Press, California, 2005), p. 208
4. R. Gardner, J. Wilkerson, J.C. Johnson, Intervirology 36, 99–112 (1993)
5. A. Pearson, A. Coen, J. Virol. 76, 10821–10828 (2002)