N. ANURADHA. \(r_c\)-operator on topological spaces. Malaya Journal of Matematik, India, v. 8, n. 04, p. 2026–2028, 2020. DOI: 10.26637/MJM0804/0119. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/1835. Acesso em: 16 jul. 2024.