1. Sexual dimorphism in Single Comb Rhode Island Red down colour;Byerley;J. Hered.,1936
2. Hagedoorn, A. L., 1946. Poultry Farmer, London, England, March 3, 1946 Issue.
3. Poultry Breeding Applied;Hays,1943
4. Auto-sex linkage in the domestic fowl;Jaap;Poult. Sci.,1941
5. The wing-spot method for colour sexing Rhode Island Red and New Hampshire chicks;Jaap;Circular C-121, Oklahoma Agric. Exp. Station,1946