GNING, M. T. Calculations of Energy Levels of the Singly Excited States (1snl) 1,3Lp for Heliumlike Ions with Z ≤ 12. European Journal of Applied Physics, [S. l.], v. 4, n. 6, p. 11–19, 2022. DOI: 10.24018/ejphysics.2022.4.6.219. Disponível em: https://www.ej-physics.org/index.php/ejphysics/article/view/219. Acesso em: 28 jan. 2023.