@article{câmara_monteiro_paiva_gomes_velho_2000,  title={Towards a unified framework for spatial data models},  volume={7},  ISSN={0104-6500},  url={https://doi.org/10.1590/S0104-65002000000200003},  DOI={10.1590/S0104-65002000000200003},  number={1},  journal={Journal of the Brazilian Computer Society},  publisher={Sociedade Brasileira de Computação},  author={Câmara, Gilberto and Monteiro, Antônio Miguel Vieira and Paiva, João Argemiro and Gomes, Jonas and Velho, Luiz},  year={2000},  pages={17–25} }