TY  - JOUR
AU  - Halava, Vesa
AU  - Harju, Tero
TI  - Undecidability of infinite post correspondence problem for instances of size 9
JO  - RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
PY  - 2006
SP  - 551
EP  - 557
VL  - 40
IS  - 4
PB  - EDP-Sciences
UR  - http://www.numdam.org/articles/10.1051/ita:2006039/
DO  - 10.1051/ita:2006039
LA  - en
ID  - ITA_2006__40_4_551_0
ER  -