Portaluppi, Roberto, et al. “Tolerance of Small Graine Cereal Genotypes to Aluminum on Hydroponic and Field Cultivation”. Pesquisa Agropecuaria Brasileira, vol. 45, no. 2, Jan. 2011, pp. 178-85, doi:10.1590/S1678-3921.pab2010.v45.5092.