Language Processing and Intelligent Information Systems : 20th International Conference, IIS 2013, Warsaw, Poland, June 17-18, 2013, Proceedings - Mieczys.aw A. K.opotek, Jacek Koronacki, Ma.gorzata Marciniak, Agnieszka Mykowiecka, S.awomir T. Wierzcho ((Lecture Notes in Computer Science))