ANTSYGINA, T.; CHISHKO, K. Helium atom in an external electric field: Exact diagonalization. ФІЗИКА НИЗЬКИХ ТЕМПЕРАТУР, Харків, Україна, v. 40, n. 9, p. 1035–1044, 2014. DOI: 10.1063/1.4894414 . Disponível em: http://80.92.230.95/index.php/fnt/article/view/f40-1035e. Acesso em: 11 лис. 2025.