@article{fadigas_amaral sobrinho_anjos_mazur_2010,  title={Background levels of some trace elements in weathered soils from the Brazilian Northern region},  volume={67},  ISSN={0103-9016},  url={https://doi.org/10.1590/S0103-90162010000100008},  DOI={10.1590/S0103-90162010000100008},  number={1},  journal={Scientia Agricola},  publisher={Escola Superior de Agricultura "Luiz de Queiroz"},  author={Fadigas, Francisco Souza and Amaral Sobrinho, Nelson Moura Brasil do and Anjos, Lucia Helena Cunha dos and Mazur, Nelson},  year={2010},  month={Jan},  pages={53–59} }