1. Berstel, J., Perrin, D.: Theory of Codes. Academic Press Inc., New York (1985)
2. Devolder, J., Latteux, M., Litovsky, I., Staiger, L.: Codes and infinite words. Acta Cybernetica 11(4), 241–256 (1994)
3. Staiger, L.: On infinitary finite length codes. Informatique Théorique et Applications 20(4), 483–494 (1986)
4. Van, D.L.: Contribution to Combinatorics on Words. PhD thesis, Humboldt University, Berlin (1985)
5. Mohri, M., Pereira, F., Riley, M.: Speech recognition with weighted finite-state transducers. Springer, Heidelberg (2007)