J. C. da S. M. de Souza and M. A. Trindade Neto, “Dietary levels of methionine plus cystine and chelated copper on the chemical composition of eggs and yolk cholesterol of 49-week-old brown laying hens”, Semina: Ciênc. Agrár., vol. 41, no. 1, pp. 269–282, Jan. 2020.