Existence of Positive Solutions of Second-order Periodic Boundary Value Problems with Sign-Changing Green's Function

Cheng-hua GAO, Fei ZHANG, Ru-yun MA

Acta Mathematicae Applicatae Sinica(English Series) . 2017, (2): 263 -268 . DOI: 10.1007/s10255-017-0657-2