Mohammad Taghi Darvishi and  Samad Kheybari,  An Approximate Solution of the Classical Van der Pol Oscillator Coupled Gyroscopically to a Linear Oscillator Using Parameter-Expansion Method.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    August 2011, vol. 56(8). 1423 - 1425
    [viewed 16 April 2024]. Available from: https://publications.waset.org/pdf/15920.