Energy levels of the improved Tietz oscillator in external magnetic and Aharonov-Bohm flux fields: the Pekeris approximation recipeE. S. Eyube, H. Samaila, I. B. Okon, P. U. Tanko, C. A. Onate, D. Yabwa, P. P. Notani and E. OmugbeEur. Phys. J. Plus, 138 3 (2023) 251DOI: https://doi.org/10.1140/epjp/s13360-023-03830-8