Sultan, S. ., M. . Hamed, and N. . Osman. “Evaluation of Protection Efficiency of Different Vaccination Programs Against Velogenic Newcastle Disease Virus in Broiler Chickens: Comparative in Field and in Laboratory Studies”. The Thai Journal of Veterinary Medicine, vol. 51, no. 1, Jan. 2021, pp. 141-50, https://he01.tci-thaijo.org/index.php/tjvm/article/view/247454.