Eric Breck Yejin Choi Claire Cardie Identifying Expressions of Opinion in Context. 2683-2688 2007 conf/ijcai/2007 IJCAI http://dli.iiit.ac.in/ijcai/IJCAI-2007/PDF/IJCAI07-431.pdf db/conf/ijcai/ijcai2007.html#BreckCC07