1. Bapat, R. B., Graphs and Matrices, Springer, London, 2010. http://dx.doi.org/10.1007/978-1-84882-981-7
2. Bozkurt, S. B., Güngör, A. D., Gutman, I., C¸ evik, A. S., Randic matrix and Randic energy, MATCH Commun. Math. Comput. Chem., 64(1) (2010), 239–250.
3. Cvetkovic, D. M., Doob, M., Sachs, H., Spectra of Graphs – Theory and Application, Academic Press, New York, 1980.
4. Das, K. C., Sorgun, S., Xu, K., On the Randic energy of graphs, MATCH Commun. Math. Comput. Chem., 72(1) (2014), 227–238.
5. Ghanbari, N., On the Sombor characteristic polynomial and Sombor energy of a graph, arXiv:2108.08552, 2021. https://doi.org/10.48550/arXiv.2108.08552