1. Alur, R.: Marrying words and trees. ACM SIGMOD-SIGACT-SIGART SPDS 26, 233–242 (2007)
2. Alur, R., Madhusudan, P.: Visibly pushdown languages. ACM STC 36, 202–211 (2004)
3. Lecture Notes in Computer Science;J. Champavère,2008
4. Comon, H., Dauchet, M., Gilleron, R., Löding, C., Jacquemard, F., Lugiez, D., Tison, S., Tommas, M.: Tree Auto. Tech. and App. online (revised 2007)
5. Engelfriet, J., Maneth, S., Seidl, H.: Deciding Equiv. of Top-Down XML Transformations in Poly. Time. Journal of Comp. and Syst. Sci. (to appear, 2009)