A Survey of Two-Dimensional Automata Theory.

Katsushi Inoue Itsuo Takanami A Survey of Two-Dimensional Automata Theory. 72-91 1988 conf/imycs/1988 IMYCS db/conf/imycs/imycs1988.html#InoueT88 http://dx.doi.org/10.1007/BFb0015929