WASET
    Thanin Sitthiwirattham and  Jiraporn Reunsumrit,  Existence of Positive Solutions for Second-Order Difference Equation with Discrete Boundary Value Problem.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    May 2014, vol. 89(5). 816 - 821
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/9998364.