Nga, Nguyễn Thị Bích, et al. “Characterization of the Neuraminidase (NA) Polypeptide of the Avian Influenza Virus A H5N1 Strains in Poultry Collected During 2004 - 2009 in Vietnam”. Vietnam Journal of Biotechnology, vol. 9, no. 1, June 2012, doi:10.15625/1811-4989/9/1/1076.