Ernesto Urenda-Cázares, Armando Gallegos, Jorge Eduardo Macías-Díaz, Héctor Vargas-Rodríguez. An integral of motion for the damped cubic-quintic Duffing oscillator with variable coefficients. Commun. Nonlinear Sci. Numer. Simul., 78:104860, 2019. [doi]
Abstract is missing.