Multilingual Question Answering over Linked Data (QALD-3): Lab Overview - Cimiano, Philipp; López, Vanessa; Unger, Christina; Cabrio, Elena; Ngonga Ngomo, Axel-Cyrille; Walter, Sebastian (Information Access Evaluation. Multilinguality, Multimodality, and Visualization - 4th International Conference of the CLEF Initiative, CLEF 2013, Valencia, Spain, September 23-26, 2013. Proceedings)