1. Rational Series and Their Languages;Berstel,1988
2. Power and size of extended Watson–Crick L systems;Csima;Theoret. Comput. Sci.,2003
3. J. Honkala, K. Ruohonen, On the images of N-rational sequences counting multiplicities, Internat. J. Algebra Comput., to appear.
4. Watson–Crick D0L systems with regular triggers;Honkala;Theoret. Comput. Sci.,2001
5. Semirings, Automata, Languages;Kuich,1986