1. Banderier C., Bousquet-Mélou M., Denise A., Flajolet P., Gardy D., GouyouBeauchamps D.: On generating functions of generating trees. Proceedings of FPSAC99 11th Conference (1999) 40–52
2. Barcucci E., Del Lungo A., Pergola E., PinzaniR • ECO: a methodology for the Enumeration of Combinatorial Objects. Journal of Difference Equations and Applications 5 (1999) 435–490
3. Bassino F.: Star-height of an IN-rational series. STACS 96 LLNCS 1046 Springer (1996) 125–135
4. Berstel J., Perrin D.: Theory of codes. Academic Press (1985)
5. Berstel J., Reutenauer C.: Rational series and their languages. Springer-Verlag Berlin (1988)