J. Hinckley, R. Park, S. Xiong, W. Andersen, and D. Kooyman, “Identification and Development of Sex Specific DNA Markers in the Ostrich Using Polymerase Chain Reaction”, Int. J. Poult. Sci., vol. 4, no. 9, pp. 663–669, Aug. 2005, doi: 10.3923/ijps.2005.663.669.