LUNGU, Nicolaie, and Sorina Anamaria CIPLEA. “Ulam-Hyers Stability of Black-Scholes Equation: Dedicated to Professor Ioan A. Rus on the Occasion of His 80th Anniversary”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 61, no. 4, Dec. 2016, pp. 467-72, https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5638.