J. Denadai, A. C. Paulillo, E. M. dos S. Schmidt, G. R. V. Martins, and A. de O. T. Carrasco, “Investigation of the State of Virus Carrier of Newcastle Disease in Budgerigars (Melopsittacus undulatus)”, Int. J. Poult. Sci., vol. 12, no. 3, pp. 135–137, Feb. 2013, doi: 10.3923/ijps.2013.135.137.