@article{matkovic_valle_briand_2005,  title={Optimization of the operative conditions for heteropolyacids synthesis through ion exchange},  volume={8},  ISSN={1516-1439},  url={https://doi.org/10.1590/S1516-14392005000300022},  DOI={10.1590/S1516-14392005000300022},  number={3},  journal={Materials Research},  publisher={ABM, ABC, ABPol},  author={Matkovic, Silvana Raquel and Valle, Graciela Manuela and Briand, Laura Estefania},  year={2005},  month={Jul},  pages={351–355} }