... for Boundary Value Problems of Second-OrderFour-Point Functional Difference EquationsYang Shujie and Shi BaoInstitute of Systems Science and Mathematics, Naval Aeronautical and Astronautical University, ... Distinguished Expert Science Foundation of Naval Aeronautical and AstronauticalUniversity.References1 M. J. Gai, B. Shi, and D. C. Zhang, “Boundary value problems for second-order singular ... functional-differentialequations,” Journal of Mathematical Analysis and Applications, vol. 199, no. 1, pp. 213–230, 1996.7 F H. Wong, “Existence of positive solutions for m-Laplacian boundary value problems,”...