5Usman B A, Mani A U,Yuguda A D,et al. The effect of suplemental ascorbic acid on the development of newcastle dis- ease in japanese quail (Coturnix eoturnix Japonica) exposed to high ambient temperature[J], lnt j poul Sci,2008,7(4):328-332.
8Boucher C E,Bragg R R,Albertyn J. An alternative method for the establishment of virulence of Newcastle disease virus isolates[J]. Afri J Microbio Res,2010,4(21) :2313-2317.