A mixed initiative Q&A chatterbot systemhttp://www.library.tuc.gr/artemis/DT2009-0243/DT2009-0243.pdfhttp://purl.tuc.gr/dl/dias/3AAE16FE-E50E-42A7-BDF6-49BE2114969EA mixed initiative Q&A chatterbot systemfree2014-03-24application/pdf