1. Theoretical Computer Science;M. Ackerman,2009
2. Anderson, T., Rampersad, N., Santean, N., Shallit, J.: Finite automata, palindromes, patterns, and borders. In: CoRR, abs/0711.3183 (2007)
3. Conway, J.H.: Regular Algebra and Finite Machines. Chapman and Hall, London (1971)
4. University of Western Ontario, Department of Computer Science: Grail+ (December 2008),
http://www.csd.uwo.ca/Research/grail/index.html
5. Mäkinen, E.: On lexicographic enumeration of regular and context-free languages. Acta Cybernet. 13, 55–61 (1997)