Miranda, Diogo Alvarenga, et al. “Coloring of Egg Yolks of Laying Hens Fed With Sorghum-Based Feed With Addition of Natural and Synthetic Pigments”. Revista De Ciências Agroveterinárias, vol. 20, no. 4, Dec. 2021, pp. 302-8, doi:10.5965/223811712042021302.