Vui, T. Q., Lohr, J., Kyule, M., Zessin, K.-H., & Baumann, M. (2002). Antibody Levels against Newcastle Disease Virus, Infectious Bursal Disease Virus and Avian Influenza Virus in Rural Chickens in Viet Nam. International Journal of Poultry Science, 1(5), 127–132. https://doi.org/10.3923/ijps.2002.127.132