@article{zedan_2009,  title={New approach for tanh and extended-tanh methods with applications on Hirota-Satsuma equations},  volume={28},  ISSN={1807-0302},  url={https://www.scielo.br/j/cam/a/nDVdRmWgmvMZ8459BWfNwfC/},  number={1},  journal={Computational & Applied Mathematics},  publisher={Sociedade Brasileira de Matemática Aplicada e Computacional},  author={Zedan, Hassan A.},  year={2009},  pages={1–14} }