NITHIMA HANMENG; PORAMATE PRANAYANUNTANA. A Sinusoidal Nonlinear Oscillator with Adjustable Frequency. Agriculture and Natural Resources, Bangkok, Thailand, v. 43, n. 5, p. 372–378, 2009. Disponível em: https://li01.tci-thaijo.org/index.php/anres/article/view/244845. Acesso em: 20 may. 2024.