@article{baumann_wanner_1980,  title={The 1,3,7,9-tetramethyluric acid content of cupu (Theobroma grandiflorum Schum.)},  volume={10},  ISSN={0044-5967},  url={https://doi.org/10.1590/1809-43921980102425},  DOI={10.1590/1809-43921980102425},  number={2},  journal={Acta Amazonica},  publisher={Instituto Nacional de Pesquisas da Amazônia},  author={Baumann, T. W. and Wanner, H.},  year={1980},  month={Jun},  pages={425–425} }