1. P. Cégielski, Serge Grigorieff, Irène Guessarian, Newton representation of functions over natural integers having integral difference ratios, submitted for publication.
2. Automata, Languages and Machines, vol. A;Eilenberg,1974
3. Z. Ésik, J-É. Pin, Personal communication, July 2011.
4. Finite automata and the representation of events;Myhill,1957
5. On profinite uniform structures defined by varieties of finite monoids;Pin;Int. J. Algebra Comput.,2011