SUN, YONGQI; YANG, YUANSHENG; LIN, XIAOHUI; ZHENG, WENPING. The value of the Ramsey number R4(C4). Utilitas Mathematica , [S. l.], v. 73, 2007. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/481. Acesso em: 18 apr. 2026.