Pereira, Hamilton Seron, Newton Cabral Barbosa, Marco Aurélio Carbone Carneiro, and Gaspar Henrique Korndörfer. 2007. “Evaluation of Sources and Extractors of Silicon in the Soil”. Pesquisa Agropecuaria Brasileira 42 (2):239-47. https://doi.org/10.1590/S1678-3921.pab2007.v42.7560.