Yuki Noyori, Hironori Washizaki, Yoshiaki Fukazawa, Hideyuki Kanuka, Keishi Ooshima, Ryosuke Tsuchiya, “Improved Searchability of Bug Reports Using Content-based Labeling with Machine Learning of Sentences,” 12th Joint Conference on Knowledge-Based Software Engineering (JCKBSE’18), August 27-30 2018, Ionian University, Corfu, Greece