M. Benedikt and L. Segoufin, Regular tree languages definable in FO and in FO mod, ACM Trans. Computational Logic (ToCL), vol.11, issue.1, 2009.

B. Miko, Two-way unary temporal logic over trees, Logical Methods in Computer Science (LMCS), vol.5, issue.3, 2009.

B. Miko and L. Segoufin, Tree languages defined in first-order logic with one quantifier alternation, Logical Methods in Computer Science (LMCS), vol.6, issue.4, 2010.

H. Miko-laj-boja´nczykboja´nczyk, I. Straubing, and . Walukiewicz, Wreath products of forest algebras with applications to tree logics, Symposium on Logic in Computer Science (LICS), pp.255-263, 2009.

B. Miko and I. Walukiewicz, Forest algebras, Automata and Logic: History and Perspectives, pp.107-132, 2007.

B. Bollobás, Modern Graph Theory. Graduate Texts in Mathematics, 1998.

S. Eilenberg and . Automata, Languages and Machines, volume B, 1976.

P. Erdös and G. Szekeres, A combinatorial problem in geometry, Compositio Mathematica, vol.2, pp.463-470, 1935.

R. Mcnaughton and S. Papert, Counter-Free Automata Jean-´ Eric Pin. A variety theorem without complementation, Russian Mathematics (Izvestija vuzov.Matematika), vol.12, issue.39, pp.80-90, 1971.

T. Place and L. Segoufin, Deciding definability in FO 2 (<) (or XPath) on trees, Symposium on Logic in Computer Science (LICS), pp.253-262, 2010.

I. Simon, Piecewise testable events, Automata Theory and Formal Languages, pp.214-222, 1975.
DOI : 10.1007/3-540-07407-4_23

J. Stern, Complexity of some problems from the theory of automata, Information and Control, vol.66, issue.3, pp.163-176, 1985.
DOI : 10.1016/S0019-9958(85)80058-9

H. Straubing, Finite Automata, Formal Languages, and Circuit Complexity, 1994.
DOI : 10.1007/978-1-4612-0289-9

H. Straubing and D. Thérien, Partially ordered finite monoids and a theorem of I. Simon, Journal of Algebra, vol.119, issue.2, pp.393-399, 1988.
DOI : 10.1016/0021-8693(88)90067-1

D. Thérien and T. Wilke, Over words, two variables are as powerful as one quantifier alternation, Proceedings of the thirtieth annual ACM symposium on Theory of computing , STOC '98, pp.256-263, 1998.
DOI : 10.1145/276698.276749

D. Thérien and T. Wilke, Temporal Logic and Semidirect Products: An Effective Characterization of the Until Hierarchy, SIAM Journal on Computing, vol.31, issue.3, pp.777-798, 2001.
DOI : 10.1137/S0097539797322772

T. Wilke, Classifying Discrete Temporal Properties, Symposium on Theoretical Aspects of Computer Science (STACS), pp.32-46, 1999.
DOI : 10.1007/3-540-49116-3_3

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.30.8942