Machado, C.M.N. et al. 2014. Efficiency in land utilization, yield and yield components of crops in association. Pesquisa Agropecuaria Brasileira. 22, 11/12 (Apr. 2014), 1167–1183. DOI:https://doi.org/10.1590/S1678-3921.pab1987.v22.14666.