W. Narvaez-Solarte, H. S. Rostagno, P. R. Soares, L. F. Uribe-Velasquez, and M. A. Silva, “Nutritional Requirement of Calcium in White Laying Hens from 46 to 62 Wk of Age”, Int. J. Poult. Sci., vol. 5, no. 2, pp. 181–184, Jan. 2006, doi: 10.3923/ijps.2006.181.184.