KURCHENKO, Olexandr; SYNIAVSKA, Olga. MONOTONE CHAINS OF SETS IN OLYMPIAD PROBLEMS. Physical and Mathematical Education, Україна, v. 40, n. 4, p. 40–44, 2025. DOI: 10.31110/fmo2025.v40i4-06. Disponível em: https://www.fmo-journal.org/index.php/fmo/article/view/447. Acesso em: 6 jun. 2026.