Voll, Elemar, et al. “Population Dynamics of Acanthospermum Hispidum DC. Under Soil and Herbicide Management Practices”. Pesquisa Agropecuaria Brasileira, vol. 32, no. 9, Sept. 1997, pp. 897-04, https://doi.org/10.1590/S1678-3921.pab1997.v32.4734.