R. Klinger. Proceedings of the International Conference Recent Advances in Natural Language Processing 2011, page 580-585. Hissar, Bulgaria, RANLP 2011 Organising Committee, (September 2011)
R. Klinger, and C. Friedrich. Proceedings of Recent Advances in Natural Language Processing (RANLP), page 185-191. Borovets, Bulgaria, (September 2009)