Manangi, M.K., et al. “Effect of Adding Phytase to Broiler Diets Containing Low and High Phytate Phosphorus: 1. Performance, Phytate P Hydrolysis, Tibia Ash, Litter Phosphorus and Ca and P Digestion and Retention”. International Journal of Poultry Science, vol. 8, no. 10, Sept. 2009, pp. 919–928, https://doi.org/10.3923/ijps.2009.919.928.