CRISTEA, Mihai. On some cluster sets problems. Studia Universitatis Babeș-Bolyai Mathematica, [S. l.], v. 67, n. 2, p. 361–368, 2022. DOI: 10.24193/subbmath.2022.2.12. Disponível em: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/1506. Acesso em: 5 feb. 2025.