C. C. Jobim, L. Lombardi, F. A. F. de Macedo, and A. F. Branco, “Quality of corn grain silage added with soybean, sunflower or urea”, PAB, vol. 43, no. 5, pp. 649–656, Oct. 2008, doi: 10.1590/S1678-3921.pab2008.v43.373.