A priori bounds are established for periodic solutions of an nth order Rayleigh equation with delay. From these bounds, existence theorems for periodic solutions are established by means of Mawhin's continuation theorem.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-ap78-3-4, author = {Gen-Qiang Wang and Sui Sun Cheng}, title = {Periodic solutions of nth order delay Rayleigh equations}, journal = {Annales Polonici Mathematici}, volume = {79}, year = {2002}, pages = {261-266}, zbl = {1005.34064}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap78-3-4} }
Gen-Qiang Wang; Sui Sun Cheng. Periodic solutions of nth order delay Rayleigh equations. Annales Polonici Mathematici, Tome 79 (2002) pp. 261-266. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap78-3-4/