Trevor Cohn Chris Callison-Burch Mirella Lapata Constructing Corpora for the Development and Evaluation of Paraphrase Systems. 597-614 2008 34 Computational Linguistics 4 http://dx.doi.org/10.1162/coli.08-003-R1-07-044 db/journals/coling/coling34.html#CohnCL08