@article{vieira_kessler_ribeiro_silva_kunrath_2011,  title={Nutrient balance of layers fed diets with different calcium levels and the inclusion of phytase and/or sodium butyrate},  volume={13},  ISSN={1516-635X},  url={https://doi.org/10.1590/S1516-635X2011000200011},  DOI={10.1590/S1516-635X2011000200011},  number={2},  journal={Brazilian Journal of Poultry Science},  publisher={Fundação de Apoio à Ciência e Tecnologia Animal},  author={Vieira, MM and Kessler, AM and Ribeiro, AML and Silva, ICM and Kunrath, MA},  year={2011},  month={Mar},  pages={157–162} }