@article{rodrigues_mazzone_santos_cruz_fernandes_2009,  title={Optimization of the production of ethyl esters by ultrasound assisted reaction of soybean oil and ethanol},  volume={26},  ISSN={0104-6632},  url={https://doi.org/10.1590/S0104-66322009000200013},  DOI={10.1590/S0104-66322009000200013},  number={2},  journal={Brazilian Journal of Chemical Engineering},  publisher={Brazilian Society of Chemical Engineering},  author={Rodrigues, S. and Mazzone, L. C. A. and Santos, F. F. P. and Cruz, M. G. A. and Fernandes, F. A. N.},  year={2009},  month={Apr},  pages={361–366} }