[1] A. W. Goodman, On sets of acquaintances and strangers at any party, Amer. Math. Monthly, 66 (1959) 778–783.
[2] B. Furtula and I. Gutman, A forgotten topological index, J. Math. Chem., 53 (2015) 1184-1190.
[3] B. Zhou and Z. B. Du, Some Lower Bounds for Estrada Index, Iranian Journal of Mathematical Chemistry, 1 (2010)
67–72.
[4] D. Vukiˇcevi´c, L. Qiuli, J. Sedlar and T. Doˇsli´c, Lanzhou index, MATCH Commun. Math. Comput. Chem., 80 (2018)
863–876.
[5] D. Cvetkovi´c, M. Doob and H. Sachs, Spectra of Graphs-Theory and Application, Academic Press, New York, 1980.
[6] E. Estrada, Characterization of 3D molecular structure, Chem. Phys. Lett., 319 (2000) 713–718.
[7] E. Estrada, Rodr´ıguez-Val´azquez, Randi´c, M: Atomic branching in molecules, Int. J. Quant. Chem., 106 (2006)
823–832.
[8] E. Estrada, Rodr´ıguez-Val´azquez, Subgraph centrality in complex networks, Phys. Rev. E, 71 (2005).
[9] E. A. Nordhaus and J. Gaddum, On complementary graphs, Amer. Math. Monthly, 63 (1956) 175–177.
[10] G. Lorden, Blue-empty chromatic graphs, Amer. Math. monthly, 69 (1962) 114–119.
[11] I. Gutman and J. Toˇsovi´c, Testing the quality of molecular structure descriptors, Vertex-degree-based topological
indices, J. Serb. Chem. Soc., 78 (2013) 805–810.
[12] I. Gutman, Remark on the moment expansion of total π-electron energy, Theor. Chim. Acta, 83 (1992) 313–318.
[13] I. Gutman, S. Markovi´c and A. Vesovi´c, Estrada, Approximating total -electron energy in terms of spectral moments,
A quantitative approach, J. Serb. Chem. Soc., 63 (1998) 639–646.
[14] K. C. Das, Maximizing the sum of the squares of the degrees of a graph, Discrete Math., 285 (2004) 57–66.
[15] K. C. Das, K. Das and I. Gutman, Some properties of the second Zagreb index, MATCH Commun. Math. Comput.
Chem., 52 (2004) 103–112.
[16] L. Zhang and W. Baoyindureng, The Nordhaus-Goddum-type inequalities for some chemiacal indices, MATCH
Commum. Comput. Chem., 54 (2005) 189–194.
[17] S. M. Hosamani and B. Basavanagoud, New Upper Bounds for the First Zagreb Index, MATCH Commun. Math.
Comput. Chem., 74 (2015) 97–101.
[18] X. D. Chen and J. G. Qian, Bounds on the number of closed walks in a graph and its applications, Journal of
Inequalities and Applications, 199 (2014).
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