Parasyuk, I.O. (2014) “Quasiperiodic Extremals of Nonautonomous Lagrangian Systems on Riemannian Manifolds”,
Ukrains’kyi Matematychnyi Zhurnal, 66(10), pp. 1387–1406. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/2230 (Accessed: 26 April 2025).