Lagoda, V.A., Parasyuk, I.O. and Samoilenko, A.M. (2012) “Lipschitzian invariant tori of indefinite monotone system”, Ukrains’kyi Matematychnyi Zhurnal, 64(3), pp. 363–383. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2582 (Accessed: 10 April 2025).