[1] A. Balaban, Topological indices based on topological distance in molecular graphs, Pure Appl. Chem. 55 (1983) 199-206.
[2] M.R. Farahani, Computing a new version of atom-bond connectivity index of circumcoronene series of benzenoid Hk by using cut method, J. Math. Nanosci. 2 (2012) 15-20.
[3] S. Forgie, TJ. Marrie, Healthcare-associated atypical pneumonia, Semin. Respir. Crit. Care Med. 30 (2009) 67-85.
[4] M. Ghorbani, M. A. Hosseinzadeh, Computing ABC4 index of nanostar dendrimers, J. Optoelectron. Adv. Mater. 4(9) (2010) 1419-22.
[5] A. Graova´c, M. Ghorbani, A new version of atom-bond connectivity index, Acta Chimica Slovenica. 57 (2010) 609-612.
[6] I. Gutman, A formula for the Wiener number of trees and its extension to graphs containing cycles, Graph Theory Notes, 27 (1994) 9-15.
[7] J. Hopkins, CSSE Coronavirus COVID-19. Global Cases (dashboard). https://coronavirus.jhu.edu/map.html. 2021.
[8] http://www.chemspider.com/
[9] JS. Kahn, K. McIntosh, History and recent advances in coronavirus discovery, Pediatr. Infect. Dis. J. 24(11) (2005) S223-S226.
[10] V. R. Kulli, Product connectivity leap index and ABC leap index of helm graphs, Annals Pure Appl. Math. 18 (2018) 189-92.
[11] E. Mahase, Covid-19: First coronavirus was described in The BMJ in 1965, BMJ. 369 (2020) 1547.
[12] V. Sharma, R. Goswami, A. K. Madan, Eccentric connectivity index: A novel highly discriminating topological descriptor for structure–property and structure–activity studies, J. Chem. Inf. Comput. Sci. 37 (1997) 273-282.
[13] The American Society of Health-System Pharmacists.
www.acpe-accredit.org/faq-item/american-society-ofhealth-system-pharmacists/
[14] The Editorial Board. Is the World Ready for the Coronavirus? Distrust in science and institutions could be a major problem if the outbreak worsens. The New York Times. 2020.
[15] D. Vukicevi´c, Bond additive modeling 2 mathematical properties of max-min rodeg index, Croatica Chemica Acta. 54 (2010) 261-273.
[16] D. Vukicevi´c, B. Furtula, Topological index based on the ratios of geometrical and arithmetical means of end-vertex degrees of edges, J. Math. Chem. 46 (2009) 1369-1376.
[17] D. Vukicevi´c, M. Gaˇsperov, Bond additive modeling 1. Adriatic indices, Croatica Chemica Acta. 83 (2010) 243-260.
[18] H. Wiener, Structural determination of paraffin boiling points, J. Amer. Chem. Soc. 69 (1947) 17-20.
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