1. Akiyama, J., Avis, D., Era, H.: On a 1,2-factor of a graph. TRU Math. 16, 97–102 (1980)
2. Bapat, R.B.: Graphs and Matrices, 2nd edn. Hindustan Book Agency, New Delhi (2018)
3. Benediktovich, V.I.: Spectral condition for Hamiltonicity of a graph. Linear Algebra Appl. 494, 70–79 (2016)
4. Brouwer, A.E., Haemers, W.H.: Eigenvalues and perfect matchings. Linear Algebra Appl. 395, 155–162 (2005)
5. Brouwer, A.E., Haemers, W.H.: Spectra of Graphs. Springer, New York (2011)