@article{pinto_braga_rezende_garrido_veiga jr._bergter_patitucci_antunes_2000,  title={Separation of acid diterpenes of Copaifera cearensis huber ex ducke by flash chromatography using potassium hydroxide impregnated silica gel},  volume={11},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50532000000400005},  DOI={10.1590/S0103-50532000000400005},  number={4},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Pinto, Angelo C. and Braga, Waldenir F. and Rezende, Claudia M. and Garrido, Francisco M. S. and Veiga Jr., Valdir F. and Bergter, Lothar and Patitucci, Maria Lúcia and Antunes, Octávio A. C.},  year={2000},  month={Jul},  pages={355–360} }