Silva, P.C.G. da et al. 2010. Biomass and C/N ratio in intercrops of sorghum and maize with cover crops. Pesquisa Agropecuaria Brasileira. 44, 11 (Dec. 2010), 1504–1512. DOI:https://doi.org/10.1590/S1678-3921.pab2009.v44.2989.