GAL, Sorin G., and Ionuț T. IANCU. “Fredholm and Volterra Nonlinear Possibilistic Integral Equations”. Studia Universitatis Babeș-Bolyai Mathematica 66, no. 1 (March 30, 2021): 105–113. Accessed February 5, 2025. https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/1263.