1. Syntactic complexity of ideal and closed languages;Brzozowski,2011
2. State complexity of regular languages: finite versus infinite;Câmpeanu,2000
3. The distinguishability operation on regular languages;Câmpeanu,2014
4. Distinguishability operations and closures;Câmpeanu;Fundam. Inform.,2016
5. On the dissimilarity operation on finite languages;Câmpeanu,2016