Liu , Zhiyuan and Sun , Shurong. (2023). Triple Positive Solutions of Boundary Value Problems for High-Order Fractional Differential Equation at Resonance with Singularities.
            <i>Journal of Nonlinear Modeling and Analysis</i>. <i>4</i> (4).
            686-700.
         doi:10.12150/jnma.2022.686