1. Biggs, N.: Algebraic Graph Theory, 2nd edn. Cambridge University Press, Cambridge (1993)
2. Ciucu, M.: Enumeration of perfect matchings in graphs with reflective symmetry. J. Comb. Theory Ser. A 77, 67–97 (1997)
3. Ciucu, M.: Enumeration of spanning trees of the quartered Aztec diamond. In: Special Session on Combinatorics and Enumerative Geometry, AMS Meeting #931, University of Louisville, Louisville, KY, March 21, 1998 (Abstract Issue: 19/2)
4. Cvetković, D., Doob, M., Gutman, I., Torgašev, A.: Recent results in the theory of graph spectra. Ann. Discret. Math. 36 (1988)
5. Kenyon, R.W., Propp, J.G., Wilson, D.B.: Trees and matchings. Electron. J. Comb. 7 (2000). Research Paper 25, 34 pp