Aznabayev D, Bekbaev A, Ishmukhamedov I, Korobov V, Turmaganbet A. Nonrelativistic ionization energy levels of a helium atom. Phys. Sci. Technol. [Internet]. 2016 Oct. 3 [cited 2024 Nov. 23];2(1). Available from: https://phst.kaznu.kz/index.php/journal/article/view/63