@article{sombroek_2000,  title={Amazon landforms and soils in relation to biological
          diversity},  volume={30},  ISSN={0044-5967},  url={https://doi.org/10.1590/1809-43922000301100},  DOI={10.1590/1809-43922000301100},  number={1},  journal={Acta Amazonica},  publisher={Instituto Nacional de Pesquisas da Amazônia},  author={Sombroek, Wim},  year={2000},  month={Jan},  pages={81–81} }