Nasreen Abdul Jaleel Andrés Corrada-Emmanuel Qi Li Xiaoyong Liu Courtney Wade James Allan UMass at TREC 2003: HARD and QA. 715-725 2003 TREC http://trec.nist.gov/pubs/trec12/papers/umass-amherst.hard.qa.pdf db/conf/trec/trec2003.html#JaleelCLLWA03