ZHENG, BAIGONG; YANG, YUANSHENG; XU, XIRONG. An upper bound for the crossing number of bubble-sort graph Bn. Utilitas Mathematica , [S. l.], v. 101, 2016. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1103. Acesso em: 7 may. 2026.