@article{walker_2009,  title={Omnivory and resource - sharing in nutrient - deficient Rio Negro waters: stabilization of biodiversity?},  volume={39},  ISSN={0044-5967},  url={https://doi.org/10.1590/S0044-59672009000300017},  DOI={10.1590/S0044-59672009000300017},  number={3},  journal={Acta Amazonica},  publisher={Instituto Nacional de Pesquisas da Amazônia},  author={Walker, Ilse},  year={2009},  month={Sep},  pages={617–626} }