Tudorache, Alexandru, and Rodica Luca. “Positive Solutions to a System of Psi-Riemann–Liouville Fractional Differential Equations With Coupled Boundary Conditions”. Nonlinear Analysis: Modelling and Control 31 (July 15, 2026): 1–24. Accessed July 26, 2026. https://www.zurnalai.vu.lt/nonlinear-analysis/article/view/47756.