@article{harvey_lawson_2001,  title={Lefschetz-Pontrjagin duality for differential characters},  volume={73},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652001000200001},  DOI={10.1590/S0001-37652001000200001},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={HARVEY, REESE and LAWSON, BLAINE},  year={2001},  month={Jun},  pages={145–159} }