Symplectic analysis of deformations of slowly perturbed completely integrable finite-dimensional Hamiltonian systems and associated adiabatic invariants. Neliniini Kolyvannya, [S. l.], v. 2, n. 1, p. 83–91, 1999. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/42. Acesso em: 22 jan. 2026.