Unbounded upper and lower solution method for third-order boundary-value problems on the half-line. Bai, Chuanzhi; Li, Chunhong — 2009 Electronic Journal of Differential Equations (EJDE) [electronic only]
Multiple positive solutions of fourth-order four-point boundary-value problems with changing sign coefficient. Fang, Zheng; Li, Chunhong; Bai, Chuanzhi — 2008 Electronic Journal of Differential Equations (EJDE) [electronic only]