BRAHA, Naim L., and Valdete LOKU. “Statistical Korovkin and Voronovskaya Type Theorem for the Ces´aro Second-Order Operator of Fuzzy Numbers”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 65, no. 4, Nov. 2020, pp. 561–574, doi:10.24193/subbmath.2020.4.06.