[1] J. Bečvář: Real time and complexity problems in automata theory. Kybernetika I, č. 6 (1965), 476-498.
[2] S. C. Kleene:
Representation of events in nerve nets and finite automata. Automata Studies, Princeton 1956.
MR 0077478
[3] J. Myhill: Linear bounded automata. WADD technical note 60-165.
[5] C. E. Shannon: Universal Turing machine with two internal states. Automata Studies, Princeton 1956.
[6] Wang, Hao:
A variant to Turing's theory of calculating machines. JACM 4 (1957), 63-92
MR 0098029