Fleck, Nilson Gilberto, and Ribas Antonio Vidal. “Effects of Physical Methods of Weed Control on Sunflower Agronomic Characteristics”. Pesquisa Agropecuaria Brasileira 28, no. 11 (November 1, 1993): 1307–1318. Accessed March 26, 2026. https://apct.sede.embrapa.br/pab/article/view/4000.