Weijiao Xu, Huaying Wang
      Positive solution of a nonlinear four-point boundary-value problem
      Nonlinear Analysis and Differential Equations, Vol. 5, 2017, no. 8, 299-308
      https://doi.org/10.12988/nade.2017.71018

Copyright © 2017 Weijiao Xu and Huaying Wang. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.