G. P. Mateus, C. A. C. Crusciol, Émerson Borghi, C. M. Pariz, C. Costa, and J. P. F. da Silveira, “Nitrogen fertilization on sorghum intercropped with grass in a no‑tillage system”, PAB, vol. 46, no. 10, pp. 1161–1169, Jan. 2012.