Generating Referring Expressions: Making Referents Easy to Identify Ivandré Paraboni author Kees van Deemter author Judith Masthoff author 2007 text journal article Computational Linguistics continuing periodical academic journal paraboni-etal-2007-generating 10.1162/coli.2007.33.2.229 https://aclanthology.org/J07-2004/ 2007 33 2 229 254