Onunkwo, O. and Okoye, J. (1991) “First report of an infectious bursal disease outbreak in a vaccinated chicken flock in Anambra State, Nigeria”, Revue d’élevage et de médecine vétérinaire des pays tropicaux. Montpellier, France, 44(4), pp. 411–414. doi: 10.19182/remvt.9144.