1.
Diestel, R.: Graph theory. Springer, Heidelberg (2010).
2.
Stanley, R.P.: Algebraic Combinatorics: Walks. Springer, New York, USA (2018).
3.
Bollobás, B.: Graph theory: an introductory course. Springer Verlag, New York (1979).
4.
Bollobás, B.: Combinatorics: set systems, hypergraphs, families of vectors and  combinatorial probability. Cambridge University Press, Cambridge (1986).
5.
Lint, Jacobus Hendricus van, 1932- author: Introduction to coding theory. Springer, Berlin, [Germany] (1999).
6.
Ball, K.M.: Strange curves, counting rabbits, and other mathematical explorations. Princeton University Press, Princeton, N.J. (2003).
7.
Albert, A.A., Sandler, R.: An introduction to finite projective planes. Dover Publications, Inc, Mineola, New York (2015).