Oliveira, Milson Lopes de, et al. “Performance of a No-Tillage Seeder, in Two Soils With Different Types of Vegetable Coverages”. Pesquisa Agropecuaria Brasileira, vol. 35, no. 7, July 2000, pp. 1455-63, doi:10.1590/S1678-3921.pab2000.v35.5918.