An approximation to the Woods–Saxon potential based on a contact interaction C. Romaniega, M. Gadella, R. M. Id Betan and L. M. Nieto Eur. Phys. J. Plus, 135 4 (2020) 372 Published online: 27 April 2020 DOI: 10.1140/epjp/s13360-020-00388-7