OKBQA: an Open Collaboration Framework for Development of Natural Language Question-Answering over Knowledge Bases. - Jin-Dong Kim; Christina Unger; Axel-Cyrille Ngonga Ngomo; André Freitas; YoungGyun Hahm; Jiseong Kim; Gyu-Hyun Choi; Jeonguk Kim; Ricardo Usbeck; Myoung-Gu Kang; Key-Sun Choi (ISWC (Posters, Demos & Industry Tracks), 2017)