ANASTASSIOU, George A., and Merve KESTER. 2016. “Global Smoothness Preservation and Simultaneous Approximation by Multivariate Discrete Operators: Dedicated to Professor Gheorghe Coman on the Occasion of His 80th Anniversary”. Studia Universitatis Babeș-Bolyai Mathematica 61 (3):257-78. https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5566.