MARTYNYUK, A. A. Concerning the problem on stability of analytical motions . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 4, p. 534–540, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8589. Acesso em: 12 jan. 2026.