1. The undecidability of the domino problem;Berger;Mem. Amer. Math. Soc.,1966
2. Propositional dynamic logic of regular programs;Fischer;J. Comput. System Sci.,1979
3. A simple highly undecidable domino problem (or, A lemma on infinite trees with applications);Harel,1984
4. Recurring dominoes: Making the highly undecidable highly understandable;Harel,1983
5. Dynamic logic;Harel,1983