Silva, V. O., E. Lopes, E. Andrade, R. V. Sousa, M. G. Zangeronimo, and L. J. Pereira. “Use of Biodiesel Co-Products (Glycerol) As Alternative Sources of Energy in Animal Nutrition: A Systematic Review”. Archivos De Medicina Veterinaria, vol. 46, no. 1, Apr. 2014, pp. 111-20, doi:10.4067/S0301-732X2014000100015.