COMĂNECI, Andrei. “On Fryszkowski’s Problem”. Studia Universitatis Babeș-Bolyai Mathematica 62, no. 4 (December 30, 2017): 537–542. Accessed September 1, 2025. https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/1919.