- Fundam. Inform. (2011)
- Int. J. Found. Comput. Sci. 22(7):1577-1592 (2011)
- Int. J. Found. Comput. Sci. 22(7):1533-1548 (2011)
- Where Mathematics, Computer Science, Linguistics and Biology Meet, page 139-148. Kluwer Academic Publishers, (2001)
- Words, Languages & Combinatorics, page 73-87. World Scientific, (2000)
- Electronic Colloquium on Computational Complexity ECCC (2000)
- New Developments in Formal Languages and Applications, volume 113 of Studies in Computational Intelligence, Springer, (2008)
- Encyclopedia of Complexity and Systems Science, Springer, (2009)
- AFL, page 197-210. (2011)
- AFL, page 257-268. (2008)
- Automata, page 208-221. Luniver Press, Frome, UK, (2008)
- LATA, Report 35/07, page 331-342. Research Group on Mathematical Linguistics, Universitat Rovira i Virgili, Tarragona, (2007)
- LATA, Report 35/07, page 343-354. Research Group on Mathematical Linguistics, Universitat Rovira i Virgili, Tarragona, (2007)
- Automata, page 71-90. DMTCS, (2010)
- JAC, page 156-167. Turku Center for Computer Science, (2010)
- JAC, page 13-30. Turku Center for Computer Science, (2010)
- DCFS, page 138-149. MTA SZTAKI, Hungarian Academy of Sciences, Budapest, Hungary, (2003)
- DCFS, Report No. 586, page 55-69. Department of Computer Science, The University of Western Ontario, Canada, (2002)
- DCFS, Preprint Nr. 16, page 103-114. Fakultät für Informatik, Universität Magdeburg, Magdeburg, Germany, (2001)
- NCMA, volume 282 of books@ocg.at, page 179-192. Austrian Computer Society, (2011)


author