F. HAQ; K. SHAH; G. RAHMAN; M. SHEHZAD. Existence and Uniqueness of Positive Solution to Boundary Value Problem of Fractional Differential Equations . Sindh University Research Journal - SURJ (Science Series), [S. l.], v. 48, n. 2, 2016. Disponível em: https://sujo.usindh.edu.pk/index.php/SURJ/article/view/4939. Acesso em: 2 apr. 2026.