Bussière, Hélène, et al. “Subspecies Identification With MtDNA and Morphometrics in Captive Palm Cockatoos, Probosciger Aterrimus”. Journal of Zoo and Aquarium Research, vol. 2, no. 1, Jan. 2014, pp. 1-7, doi:10.19227/jzar.v2i1.60.