Santos, J.C.F. et al. 2002. Effect of extracts of coffee and rice husks upon emergence and growth of the slender amaranth. Pesquisa Agropecuaria Brasileira. 37, 6 (Jun. 2002), 783–790. DOI:https://doi.org/10.1590/S1678-3921.pab2002.v37.6403.