no. 4
A semigroup characterization of dot-depth one languages
RAIRO. Informatique théorique, Tome 17 (1983) no. 4, pp. 321-330. 
@article{ITA_1983__17_4_321_0,
     author = {Knast, Robert},
     title = {A semigroup characterization of dot-depth one languages},
     journal = {RAIRO. Informatique th\'eorique},
     pages = {321--330},
     publisher = {EDP-Sciences},
     volume = {17},
     number = {4},
     year = {1983},
     mrnumber = {743892},
     zbl = {0522.68063},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1983__17_4_321_0/}
}
TY  - JOUR
AU  - Knast, Robert
TI  - A semigroup characterization of dot-depth one languages
JO  - RAIRO. Informatique théorique
PY  - 1983
SP  - 321
EP  - 330
VL  - 17
IS  - 4
PB  - EDP-Sciences
UR  - http://www.numdam.org/item/ITA_1983__17_4_321_0/
LA  - en
ID  - ITA_1983__17_4_321_0
ER  - 
%0 Journal Article
%A Knast, Robert
%T A semigroup characterization of dot-depth one languages
%J RAIRO. Informatique théorique
%D 1983
%P 321-330
%V 17
%N 4
%I EDP-Sciences
%U http://www.numdam.org/item/ITA_1983__17_4_321_0/
%G en
%F ITA_1983__17_4_321_0
Knast, Robert. A semigroup characterization of dot-depth one languages. RAIRO. Informatique théorique, Tome 17 (1983) no. 4, pp. 321-330. http://www.numdam.org/item/ITA_1983__17_4_321_0/

1. J. A. Brzozowski, Hierarchies of a Periodic Languages, R.A.I.R.O., Informatique Théorique, Vol. 10, No. 8, 1976, pp. 33-49. | Numdam | MR

2. J. A. Brzozowski a,d R. Knast, The Dot Depth Hierarchy of Star-Free Languages is Infinité, J. Computer and System Sc., Vol. 16, No. 1, 1978, pp. 37-55. | MR | Zbl

3. R. S. Cohen and J. A. Brzozowski, Dot-Depth of Star-Free Events, J. Computer and System Sc., Vol. 5, 1971, pp. 1-16. | MR | Zbl

4. S. Eilenberg, Automata, Languages and Machines, Vol. B, Academie Press, New York, 1976. | MR | Zbl

5. R. Knast, Some Theorems on Graph Congruences, R.A.I.R.O., Informatique Théorique, Vol. 17, No. 4, pp. 331-342. | Numdam | MR

6. I. Simon, Hierarchies of Events with Dot-Depth One, Dissertation, University of Waterloo, Canada, 1972. | MR