M. A. Aizerman, L. A. Gusev, L. I. Rozonoér, I. M. Smirnova, and A. A. Tal'. The algorithmic insolubility of the problem of recognizing the representability of recursive events in finite automata. English translation of XXXVII 426. Automation and remote control, vol. 22 (1961), pp. 646–652.
Joseph S. Ullian · Journal of Symbolic Logic · 1972
M. A. Aizerman, L. A. Gusev, L. I. Rozonoér, I. M. Smirnova, and A. A. Tal'. The algorithmic insolubility of the problem of recognizing the representability of recursive events in finite automata. English translation of XXXVII 426. Automation and remote control, vol. 22 (1961), pp. 646–652. - Volume 37 Issue 2