Lin, Muren; Wei, Zhen The existence of almost periodic solutions of second order nonlinear systems. (Chinese. English summary) Zbl 1199.34204 Acta Math. Sci., Ser. A, Chin. Ed. 29, No. 1, 10-19 (2009). Summary: This paper discusses some second order nonlinear systems. By means of averaging, some sufficient conditions for the existence of almost periodic solutions of are obtained. Two particular systems are presented. MSC: 34C27 Almost and pseudo-almost periodic solutions to ordinary differential equations 34C29 Averaging method for ordinary differential equations Keywords:almost periodic solution; method of averaging; eigenvalue PDFBibTeX XMLCite \textit{M. Lin} and \textit{Z. Wei}, Acta Math. Sci., Ser. A, Chin. Ed. 29, No. 1, 10--19 (2009; Zbl 1199.34204)