@article{arpini_cubides-román_javarini_araújo_david_santos_romão_neto_lacerda_2019,  title={Simple Niobium Catalysts Applied in Reflux and Ultrasound-Assisted Systems for Biofuel Synthesis},  volume={30},  ISSN={0103-5053},  url={https://doi.org/10.21577/0103-5053.20190099},  DOI={10.21577/0103-5053.20190099},  number={9},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Arpini, Bruno H. and Cubides-Román, Diana C. and Javarini, Clara L. and Araújo, Milena C. de and David, Geraldo F. and Santos, Reginaldo B. dos and Romão, Wanderson and Neto, Alvaro C. and Lacerda, Valdemar},  year={2019},  month={Sep},  pages={1897–1905} }