ABEL, Ulrich. “Operator Norms of Gauß-Weierstraß Operators and Their Left Quasi Interpolants”. Studia Universitatis Babeș-Bolyai Mathematica 64, no. 2 (June 30, 2019): 225–237. Accessed February 5, 2025. https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/2261.