Krisztian Balog Gilad Mishne Maarten de Rijke Why Are They Excited? Identifying and Explaining Spikes in Blog Mood Levels. 2006 conf/eacl/2006 EACL http://acl.ldc.upenn.edu/E/E06/E06-2031.pdf db/conf/eacl/eacl2006.html#BalogMR06