S. Sattar, K. Naeem, Z. Ahmed, and S. Malik, “Influence of Virus Strain on the Efficacy of Vaccine Against Avian Influenza Virus Subtype H7N3”, Int. J. Poult. Sci., vol. 6, no. 12, pp. 989–993, Nov. 2007, doi: 10.3923/ijps.2007.989.993.