@article{lopez galvan_2023,  title={An Approximate Closed Formula for European Mortgage Options},  volume={24},  ISSN={2676-0029},  url={https://doi.org/10.5540/tcam.2023.024.03.00395},  DOI={10.5540/tcam.2023.024.03.00395},  number={3},  journal={Trends in Computational and Applied Mathematics},  publisher={Sociedade Brasileira de Matemática Aplicada e Computacional - SBMAC},  author={LOPEZ GALVAN, A. M.},  year={2023},  month={Jul},  pages={395–410} }