A. Brandstädt, V. B. Le, and J. P. Spinrad, Graph classes: a survey, SIAM Monographs, 1999.
DOI : 10.1137/1.9780898719796

J. Cai, M. Fürer, and N. Immerman, An optimal lower bound on the number of variables for graph identification, Combinatorica, vol.9, issue.No. 4, pp.389-410, 1992.
DOI : 10.1007/BF01305232

J. H. Kim, O. Pikhurko, J. Spencer, and O. Verbitsky, How complex are random graphs in first order logic? Random Structures and Algorithms, pp.119-145, 2005.

O. Pikhurko, J. Spencer, and O. Verbitsky, Succinct definitions in the first order theory of graphs. Accepted for publication in Annals of Pure and Applied Logic. (arxiv.org/abs/math

O. Pikhurko, H. Veith, and O. Verbitsky, First order definability of graphs: tight bounds on quantifier rank, 2004.

F. Ramsey, On a problem of formal logic, Proc. London Math. Soc. 2-nd series, pp.264-286, 1930.

J. Spencer, The strange logic of random graphs, 2001.
DOI : 10.1007/978-3-662-04538-1