Alexandra Balahur Zornitsa Kozareva Andrés Montoyo Determining the Polarity and Source of Opinions Expressed in Political Debates. 468-480 2009 CICLing https://doi.org/10.1007/978-3-642-00382-0_38 conf/cicling/2009 db/conf/cicling/cicling2009.html#BalahurKM09