Estrada, E.; Gutman, I. A Topological Index Based on Distances of Edges of Molecular Graphs. Journal of Chemical Information and Computer Science 36, 1996, 850-853.

Estrada, E.; Gutman, I. A Topological Index Based on Distances of Edges of Molecular Graphs. Journal of Chemical Information and Computer Science 36, 1996, 850-853.