Joao Filgueiras, Silvio Amir. POPSTAR at RepLab 2013: Polarity for Reputation Classification. In Pamela Forner, Roberto Navigli, Dan Tufis, Nicola Ferro, editors, Working Notes for CLEF 2013 Conference , Valencia, Spain, September 23-26, 2013. Volume 1179 of CEUR Workshop Proceedings, CEUR-WS.org, 2013. [doi]