1. V. Bruyère and O. Carton. Automata on linear orderings. In J. Sgall, A. Pultr, and P. Kolman, editors, MFCS’2001, volume 2136 of Lect. Notes in Comput. Sci., pages 236–247, 2001. IGM report 2001-12.
2. J. R. Büchi. Weak second-order arithmetic and finite automata. Z. Math. Logik und grundl. Math., 6:66–92, 1960.
3. J. R. Büchi. On a decision method in the restricted second-order arithmetic. In Proc. Int. Congress Logic, Methodology and Philosophy of science, Berkeley 1960, pages 1–11. Stanford University Press, 1962.
4. J. R. Büchi. Transfinite automata recursions and weak second order theory of ordinals. In Proc. Int. Congress Logic, Methodology, and Philosophy of Science, Jerusalem 1964, pages 2–23. North Holland, 1965.
5. Y. Choueka. Finite automata, definable sets, and regular expressions over ωn- tapes. J. Comput. System Sci., 17(1):81–97, 1978.