Pacheco, Leandro Pereira, et al. “Nutrient Cycling by Cover Crops and Yield of Soybean and Rice in No-Tillage”. Pesquisa Agropecuaria Brasileira, vol. 48, no. 9, Dec. 2013, pp. 1228-36, doi:10.1590/S1678-3921.pab2013.v48.15282.