The third-order perturbed Korteweg-de Vries equation for shallow water waves with a non-flat bottomM. Fokou, T. C. Kofané, A. Mohamadou and E. YombaEur. Phys. J. Plus, 132 10 (2017) 410DOI: https://doi.org/10.1140/epjp/i2017-11709-0