Periodic solutions of p-Laplacian equations with singularities

In this paper, the problem of existence of periodic solution is studied for p-Laplacian Liénard equations with singular at x=0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$x=0$\end{document} and x=+∞\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$x=+\infty$\end{document}. By using the topological degree theory, some new results are obtained, and an example is given to illustrate the effectiveness of our results. Our research enriches the contents of second order differential equations with singularity.