El-Samee , L. D. A.; El-Wardany, I.; Ali, N. G.; Abo-El-Azab, O. Egg Quality, Fertility and Hatchability of Laying Quails Fed Diets Supplemented With Organic Zinc, Chromium Yeast or Mannan Oligosaccharides. Int. J. Poult. Sci. 2012, 11 (3), 221–224. https://doi.org/10.3923/ijps.2012.221.224.