STAFF, E. Содержание 2 (69) 2019. Recent Contributions to Physics, [S. l.], v. 2019, n. 2, p. 152–155, 2019. Disponível em: https://bph.kaznu.kz/index.php/zhuzhu/article/view/1196. Acesso em: 15 дек. 2025.