1. On universal traps;Antelmann;EIK,1979
2. Recognition of topological invariants by iterative arrays;Beyer,1970
3. Automata on a two-dimensional tape;Blum,1967
4. On the power of the compass;Blum,1978
5. On the capability of finite automata in 2 and 3 dimensional space;Blum,1977