@article{silva_santos_ramalho_figueroa-villar_2006,  title={Concerning the FERMO concept and Pearson's Hard and Soft acid-base principle},  volume={17},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50532006000200002},  DOI={10.1590/S0103-50532006000200002},  number={2},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Silva, Rodrigo R. da and Santos, Joana M. and Ramalho, Teodorico C. and Figueroa-Villar, J. Daniel},  year={2006},  month={Mar},  pages={223–226} }