Rocha, Francisco Eduardo de Castro, Evandro Chartuni Mantovani, Serge Bertaux, and J. C. Garcia. 1992. “Comparison of Maize Seeders Concerning the Acquisition Price and Operational Efficiency”. Pesquisa Agropecuaria Brasileira 27 (5):751-57. https://doi.org/10.1590/S1678-3921.pab1992.v27.3707.