In this article we consider equations of the type$x''+g(x)=0$ and $x''+ f(x) x'^2 + g(x)=0.$ The Neumann boundaryvalue problem is considered. For $f$ and $g$ polynomials weprovide the multiplicity results. These results are based on athorough analysis of a phase plane. The existence of period annuliis concerned.
@article{6, title = {Period annuli and multiple solutions for two-point BVP}, journal = {Tatra Mountains Mathematical Publications}, volume = {43}, year = {2009}, doi = {10.2478/tatra.v43i0.6}, language = {EN}, url = {http://dml.mathdoc.fr/item/6} }
Atslega, Svetlana; Sadyrbaev, Felikss. Period annuli and multiple solutions for two-point BVP. Tatra Mountains Mathematical Publications, Tome 43 (2009) . doi : 10.2478/tatra.v43i0.6. http://gdmltest.u-ga.fr/item/6/