@article{guimarães_morais_urquiaga_boddey_alves_2008,  title={Bradyrhizobium strain and the 15N natural abundance quantification of biological N2 fixation in soybean},  volume={65},  ISSN={0103-9016},  url={https://doi.org/10.1590/S0103-90162008000500011},  DOI={10.1590/S0103-90162008000500011},  number={5},  journal={Scientia Agricola},  publisher={Escola Superior de Agricultura "Luiz de Queiroz"},  author={Guimarães, Ana Paula and Morais, Rafael Fiusa de and Urquiaga, Segundo and Boddey, Robert Michael and Alves, Bruno José Rodrigues},  year={2008},  pages={516–524} }