Approximate Solution for the Duffing-Harmonic Oscillator by the Enhanced Cubication Method

Paal, E., & Virkepu, J. (2008). Note on 2d Binary Operadic Harmonic Oscillator. Journal of Forensic Biomechanics, 2(3), 221-225. https://www.airitilibrary.com/Article/Detail?DocID=20902689-200809-201011150053-201011150053-221-225
Pepore, S., & Sukbot, B. (2014). Schwinger Method for Dual Damped Oscillators. Chinese Journal of Physics, (), 1-7. https://doi.org/10.6122/CJP.20150803
Pepore, S., & Sukbot, B. (2015). Schwinger Method for Dual Damped Oscillators. Chinese Journal of Physics, 53(5), 100002-1-100002-7. https://doi.org/10.6122/CJP.20150803
Ikot, A. N., Akpabio, L. E., Akpan, I. O., Umo, M. I., & Ituen, E. E. (2010). Quantum Damped Mechanical Oscillator. International Journal of Optics, 2010(), 39-44. https://doi.org/10.1155/2010/275910
Su, J. Y. (2001). Simple Solutions of the Harmonic Oscillator Integral Equation. 師大學報：數理與科技類, 46(1&2), 23-28. https://doi.org/10.6301/JNTNU.2001.46.03