no. 4
Coordinated pair systems ; part II : sparse structure of Dyck words and Ogden's lemma
RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 20 (1986) no. 4, pp. 425-439. 
@article{ITA_1986__20_4_425_0,
     author = {Ehrenfeucht, A. and Hoogeboom, H. J. and Rozenberg, G.},
     title = {Coordinated pair systems ; part {II} : sparse structure of {Dyck} words and {Ogden's} lemma},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {425--439},
     publisher = {AFCET - Gauthier-Villars},
     address = {Paris},
     volume = {20},
     number = {4},
     year = {1986},
     zbl = {0639.68076},
     mrnumber = {880845},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1986__20_4_425_0/}
}
TY  - JOUR
AU  - Ehrenfeucht, A.
AU  - Hoogeboom, H. J.
AU  - Rozenberg, G.
TI  - Coordinated pair systems ; part II : sparse structure of Dyck words and Ogden's lemma
JO  - RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
PY  - 1986
DA  - 1986///
SP  - 425
EP  - 439
VL  - 20
IS  - 4
PB  - AFCET - Gauthier-Villars
PP  - Paris
UR  - http://www.numdam.org/item/ITA_1986__20_4_425_0/
UR  - https://zbmath.org/?q=an%3A0639.68076
UR  - https://www.ams.org/mathscinet-getitem?mr=880845
LA  - en
ID  - ITA_1986__20_4_425_0
ER  - 
Ehrenfeucht, A.; Hoogeboom, H. J.; Rozenberg, G. Coordinated pair systems ; part II : sparse structure of Dyck words and Ogden's lemma. RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 20 (1986) no. 4, pp. 425-439. http://www.numdam.org/item/ITA_1986__20_4_425_0/

[EHR1] A. Ehrenfeucht, H. J. Hoogeboom and G. Rozenberg, Real-time coordinated pair systems, Dept. of Computer Science, University of Colorado at Boulder, Techn. Rep. CU-CS-259-83, 1983.

[EHR2] A. Ehrenfeucht, H. J. Hoogeboom and G. Rozenberg, Computations in Coordinated Pair Systems, Fundamenta Informaticae (to appear). | MR 873639 | Zbl 0642.68133

[EHR3] A. Ehrenfeucht, H. J. Hoogeboom and G. Rozenberg, Coordinated Pair Systems, Part 1: Dyck words and classical pumping, RAIRO-Theorical Informatics and Applications, Vol. 20, n° 4, 1986, pp. 405-424. | Numdam | MR 880844 | Zbl 0639.68075

[H] M. Harrison Introduction to formal language theory, Addison-Wesley Publ. Co., Reading, Massachussetts, 1978. | MR 526397 | Zbl 0411.68058

[O] W. F. Ogden, A Helpful Result for Proving Inherent Ambiguity, Mathematical Systems Theory, Vol. 2, 1968, pp. 191-194. | MR 233645 | Zbl 0175.27802