MITROPOLSKIY , Yu. A. Nikolai Nikolaevich Bogolyubov. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 3, p. 431–432, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8114. Acesso em: 6 dec. 2025.