Aznabayev, D.T., A.K. Bekbaev, I.S. Ishmukhamedov, V.I. Korobov, and A.B. Turmaganbet. “Nonrelativistic Ionization Energy Levels of a Helium Atom”. Physical Sciences and Technology 2, no. 1 (October 3, 2016). Accessed November 23, 2024. https://phst.kaznu.kz/index.php/journal/article/view/63.