Yan, Ping; Jiang, Jifa A necessary and sufficient condition for the oscillation of a generalized Liénard system. (Chinese. English summary) Zbl 1006.34028 Math. Appl. 13, No. 4, 16-20 (2000). MSC: 34C10 PDFBibTeX XMLCite \textit{P. Yan} and \textit{J. Jiang}, Math. Appl. 13, No. 4, 16--20 (2000; Zbl 1006.34028)
Wang, Xian The global analysis of \(\ddot x+(\alpha_1+3\alpha_3x^2)\dot x-\beta_1x+\beta_3x^3=0\). (Chinese. English summary) Zbl 0894.34032 Math. Appl. 3, No. 2, 59-64 (1990). MSC: 34C23 37G99 PDFBibTeX XMLCite \textit{X. Wang}, Math. Appl. 3, No. 2, 59--64 (1990; Zbl 0894.34032)