Applying quantum supersymmetry and perturbation theory to the energy-dependent Hulthén potential Elhadj Hocine, Rabia Yekken and Roland Lombard Eur. Phys. J. Plus, 134 11 (2019) 561 Published online: 12 November 2019 DOI: 10.1140/epjp/i2019-12921-6