@article{foletto_gratieri_oliveira_jahn_2006,  title={Conversion of rice hull ash into soluble sodium silicate},  volume={9},  ISSN={1516-1439},  url={https://doi.org/10.1590/S1516-14392006000300014},  DOI={10.1590/S1516-14392006000300014},  number={3},  journal={Materials Research},  publisher={ABM, ABC, ABPol},  author={Foletto, Edson Luiz and Gratieri, Ederson and Oliveira, Leonardo Hadlich de and Jahn, Sérgio Luiz},  year={2006},  month={Jul},  pages={335–338} }