Abolfazl Keighobadi Lamjiri Leila Kosseim Thiruvengadam Radhakrishnan Comparing the Contribution of Syntactic and Semantic Features in Closed versus Open Domain Question Answering. 679-685 2007 ICSC http://doi.ieeecomputersociety.org/10.1109/ICSC.2007.49 conf/semco/2007 db/conf/semco/icsc2007.html#LamjiriKR07