1. Anuradha, A., Balakrishnan, R.: Skew spectrum of the Cartesian product of an oriented graph with an oriented hypercube. In: Bapat, R.B., Kirkland, S.J., Prasad, K.M., Puntanen, S. (eds.) Combinatorial Matrix Theory and Generalized Inverses of Matrices, pp. 1–12. Springer, Berlin (2013)
2. Bondy, J.A., Murty, U.S.R.: Graph Theory. Gradation Texts in Mathematics, vol. 244. Springer, Berlin (2008)
3. Cavers, M., Cioabǎ, S.M., Fallat, S., Gregory, D.A., Haemers, W.H., Kirkland, S.J., McDonald, J.J., Tsatsomeros, M.: Skew-adjacency matrices of graphs. Linear Algebra Appl. 436, 4512–4529 (2012)
4. Collatz, L., Sinogowitz, U.: Spektren endlicher grafen. Abh. Math. Semin. Univ. Hambg. 21, 63–77 (1957)
5. Fan, Y., Du, W., Dong, C.: The nullity of bicyclic signed graphs. Linear Algebra Appl. 436, 242–251 (2014)