International Journal of Applied Mathematics and Machine Learning[1] J. A. Bondy and U. S. R. Murty, Graph Theory with Applications,
MacMillan, New York, NY, 1976.
[2] I. Gutman and N. Trinajstic, Graph theory and molecular orbitals:
Total 
-electron energy of alternant hydrocarbons,
Chemical Physics Letters 17(4) (1972), 535-538.
DOI: https://doi.org/10.1016/0009-2614(72)85099-1
[3] I. Gutman and K. C. Das, The first Zagreb index 30 years after,
MATCH Communication in Mathematical and in Computer Chemistry 50
(2004), 83-92.
[4] B. Zhou and N. Trinajstic, On a novel connectivity index, Journal
of Mathematical Chemistry 46(4) (2009), 1252-1270.
DOI: https://doi.org/10.1007/s10910-008-9515-z
[5] B. Zhou and N. Trinajstic, On general sum-connectivity index,
Journal of Mathematical Chemistry 47(1) (2010), 210-218.
DOI: https://doi.org/10.1007/s10910-009-9542-4
