de Graaf M, Osterhaus AD, Fouchier RA, Holmes EC (2008). "Evolutionary dynamics of human and avian metapneumoviruses". J. Gen. Virol. 89 (Pt 12): 2933–42. doi:10.1099/vir.0.2008/006957-0. PMID19008378.
de Graaf M, Osterhaus AD, Fouchier RA, Holmes EC (2008). "Evolutionary dynamics of human and avian metapneumoviruses". J. Gen. Virol. 89 (Pt 12): 2933–42. doi:10.1099/vir.0.2008/006957-0. PMID19008378.