Babić, D.; Klein, D. J.; Lukovits, I.; Nikolić, S.; and Trinajstić, N. "Resistance-Distance Matrix: A Computational Algorithm and Its Applications." Int. J. Quant. Chem.90, 166-176, 2002.Balaban, A. T. "Distance Connectivity Index." Chem. Phys. Lett.89, 399-404, 1982.Devillers, J. and Balaban, A. T. (Eds.). Topological Indices and Related Descriptors in QSAR and QSPR. Amsterdam, Netherlands: Gordon and Breach, pp. 117-119, 1999.Mercader, E.; Castro, E. A.; and Toropov, A. A. "Maximum Topological Distances Based Indices as Molecular Descriptors for QSPR. 4. Modeling the Enthalpy of Formation of Hydrocarbons from Elements." Int. J. Mol. Sci.2, 121-132, 2001.Randić, M. "Characterization of Molecular Branching." J. Am. Chem. Soc.97, 6609-6615, 1975.
是為具有 
個節點、
條邊和 
個連通分量的圖定義的圖指標，定義如下：
是圖的環秩，
是邊集，
是圖距離矩陣的第 
行（或列）中所有條目的總和。