Guo, Limin, Lishan Liu, and Yonghong Wu. “Existence of Positive Solutions for Singular Fractional Differential Equations With Infinite-Point Boundary Conditions”. Nonlinear Analysis: Modelling and Control 21, no. 5 (July 22, 2019): 635–650. Accessed May 6, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/13447.