@article{soares_beurlen_ferreira_da-silva_2007,  title={Chemical composition of gahnite and degree of pegmatitic fractionation in the Borborema Pegmatitic Province, northeastern Brazil},  volume={79},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652007000300005},  DOI={10.1590/S0001-37652007000300005},  number={3},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={Soares, Dwight R. and Beurlen, Hartmut and Ferreira, Ana C.M. and da-Silva, Marcelo R.R.},  year={2007},  month={Sep},  pages={395–404} }