DU, JIANWEI; SHAO, YANLING; SUN, XIAOLING; XU, LAN. On the harmonic index and the average eccentricity of a graph. Utilitas Mathematica , [S. l.], v. 102, 2017. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1241. Acesso em: 7 may. 2026.