Sá, Jerusa Maia e, et al. “Energy Balance for the Production of Grain, Meat, and Biofuel in Specialized and Mixed Agrosystems”. Pesquisa Agropecuaria Brasileira, vol. 48, no. 10, Dec. 2013, pp. 1323-31, doi:10.1590/S1678-3921.pab2013.v48.15179.