@article{grasel_ferrão_helfer_costa_2016,  title={Principal Component Analysis of Commercial Tannin Extracts Using Digital Images on Mobile Devices},  volume={27},  ISSN={0103-5053},  url={https://doi.org/10.5935/0103-5053.20160135},  DOI={10.5935/0103-5053.20160135},  number={12},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Grasel, Fábio S. and Ferrão, Marco F. and Helfer, Gilson A. and Costa, Adilson B.},  year={2016},  month={Dec},  pages={2372–2377} }