Zhong, Qiuyan, Xingqiu Zhang, Lufeng Gu, Lei Lei, and Zengqin Zhao. “Multiple Positive Solutions for Singular Higher-Order Semipositone Fractional Differential Equations With P-Laplacian”. Nonlinear Analysis: Modelling and Control 25, no. 5 (September 1, 2020): 806–826. Accessed April 29, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/18383.