@article{moreira_2003,  title={The shadows cast by buildings and towers in cities and by montains in the countryside},  volume={25},  ISSN={1806-1117},  url={https://doi.org/10.1590/S1806-11172003000100008},  DOI={10.1590/S1806-11172003000100008},  number={1},  journal={Revista Brasileira de Ensino de Física},  publisher={Sociedade Brasileira de Física - SBF},  author={Moreira, João Luiz Kohl},  year={2003},  pages={62–73} }