B.S. BAIZHANOV; S.S. BAIZHANOV. SOME QUESTIONS ON EXTERNAL DEFINABILITY. Известия НАН РК. Серия физико-математическая, [S. l.], n. 6, p. 138–142, 2019. Disponível em: http://91834.libg.asia/physics-mathematics/article/view/1700. Acesso em: 13 мар. 2025.