1. Albert, J. and Culik, K. II (1979), Test sets for homomorphisms equivalence on context free languages, Inf. and Control, to appear, also Res. Rep. CS-79-39, Department of Computer Science, University of Waterloo, Waterloo, Ontario, Canada.
2. Blattner, M. and Head, T. (1979), The decidability of equivalence for deterministic finite transducers, J. Computer Syst. Sci. 19, 45–49.
3. Culik, K. II (1977), On the decidability of the sequence equivalence problem for DOL-systems, Theoretical Computer Sci. 3, 75–84.
4. Culik, K. II (1979), Some decidability results about regular and push down translations, Information Processing Letters 8, 5–8.
5. Culik, K. II (1980), Homomorphisms: Decidability, Equality and Test Sets, Proceedings of the International Symposium on Formal Languages Theory, Santa Barbara, California, Dec. 1979, to appear, also Res. Rep. CS-80-02, Department of Computer Science, University of Waterloo, Waterloo, Ontario, Canada.