@article{harper_1989,  title={The persistence of ant-following birds in small amazonian forest fragments},  volume={19},  ISSN={0044-5967},  url={https://doi.org/10.1590/1809-43921989191263},  DOI={10.1590/1809-43921989191263},  journal={Acta Amazonica},  publisher={Instituto Nacional de Pesquisas da Amazônia},  author={Harper, Lee H.},  year={1989},  pages={249–263} }