@article{florêncio_silva jr_botta filho_grandini_2003,  title={Effect of impurities on mechanical relaxation in niobium},  volume={6},  ISSN={1516-1439},  url={https://doi.org/10.1590/S1516-14392003000400020},  DOI={10.1590/S1516-14392003000400020},  number={4},  journal={Materials Research},  publisher={ABM, ABC, ABPol},  author={Florêncio, Odila and Silva Jr, Paulo Sergio and Botta Filho, Walter José and Grandini, Carlos Roberto},  year={2003},  month={Oct},  pages={541–544} }