Pyragas method and chaos in higher-order nonlinear Schrödinger equation in an optical fiber M. Bahar, B. B. Mouhammadoul, C. G. L. Tiofack, Alim and A. Mohamadou Eur. Phys. J. D, 76 6 (2022) 104 Published online: 20 June 2022 DOI: 10.1140/epjd/s10053-022-00435-1