[1] von Braunmühl B., Verbeek R.: Finite change automata. Proc. of 4th GI Conference on Theoretical Computer Science, Lecture Notes in Computer Science (LNCS) 67, Springer, Berlin (1979), 91-100. MR 0568095

[2] Hopcroft J., Ullman J.: Formal languages and their relation to automata. Addison-Wesley, 1969. MR 0237243 | Zbl 0196.01701

[3] Jančar P., Mráz F., Plátek M.: Characterization of context-free languages by erasing automata. Proc. of the symp. Mathematical Foundations of Computer Science (MFCS) 1992, Prague, Czechoslovakia, LNCS 629, Springer (1992), 307-314. MR 1255145

[4] Jančar P., Mráz F., Plátek M.: A taxonomy of forgetting automata. accepted to MFCS'93, Gdansk, Poland, to appear in LNCS, Springer (1993). MR 1265088

[5] Savitch W. J.: Relationships between nondeterministic and deterministic tape complexities. J. of Computer and System Sciences 4 (1970), 177-192. DOI 10.1016/S0022-0000(70)80006-X | MR 0266702 | Zbl 0188.33502