Feng, Haixing, and Chengbo Zhai. “Existence and Uniqueness of Positive Solutions for a Class of Fractional Differential Equation With Integral Boundary Conditions”. Nonlinear Analysis: Modelling and Control 22, no. 2 (March 15, 2017): 160–172. Accessed May 2, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/13398.