@article{helfer_magnus_böck_teichmann_ferrão_costa_2017,  title={PhotoMetrix: An Application for Univariate Calibration and Principal Components Analysis Using Colorimetry on Mobile Devices},  volume={28},  ISSN={0103-5053},  url={https://doi.org/10.5935/0103-5053.20160182},  DOI={10.5935/0103-5053.20160182},  number={2},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Helfer, Gilson A. and Magnus, Vinícius S. and Böck, Fernanda C. and Teichmann, Aline and Ferrão, Marco F. and Costa, Adilson B. da},  year={2017},  month={Feb},  pages={328–335} }