Alvaro H. SALAS S. Solution of the Duffing Helmholtz Oscillator Equation by Elementary Functions with Physics Applications. Current Perspective to Physical Science Research Vol. 7, [S. l.], p. 164–182, 2024. DOI: 10.9734/bpi/cppsr/v7/2865G. Disponível em: https://stm.bookpi.org/CPPSR-V7/article/view/13472. Acesso em: 4 jun. 2026.