@article{rocha_leite_2003,  title={Treatment of geophysical data as a non-stationary process},  volume={22},  ISSN={1807-0302},  url={https://doi.org/10.1590/S0101-82052003000200001},  DOI={10.1590/S0101-82052003000200001},  number={2},  journal={Computational & Applied Mathematics},  publisher={Sociedade Brasileira de Matemática Aplicada e Computacional},  author={Rocha, Marcus P.C. and Leite, Lourenildo W.B.},  year={2003},  pages={149–166} }