Rosolem, C. A., Bessa, M. A., Amaral, P. G. do, & Pereira, H. F. M. (1992). Soil manganese, its determination, and manganese toxicity in soybeans. Pesquisa Agropecuaria Brasileira, 27(2), 277–285. https://doi.org/10.1590/S1678-3921.pab1992.v27.3648