A. Kingori, J. Tuitoek, H. Muiruri, and A. Wachira, “Effect of Dietary Crude Protein Levels on Egg Production, Hatchability and Post-Hatch Offspring Performance of Indigenous Chickens”, Int. J. Poult. Sci., vol. 9, no. 4, pp. 324–329, Mar. 2010, doi: 10.3923/ijps.2010.324.329.