A new approach to exact optical soliton solutions for the nonlinear Schrödinger equation V. F. Morales-Delgado, J. F. Gómez-Aguilar and Dumitru Baleanu Eur. Phys. J. Plus, 133 5 (2018) 189 Published online: 18 May 2018 DOI: 10.1140/epjp/i2018-12020-4