Susanne Boll Steven C. H. Hoi Jiebo Luo Rong Jin Irwin King Dong Xu First ACM SIGMM international workshop onsocial media (WSM'09). 1161-1162 2009 ACM Multimedia http://doi.acm.org/10.1145/1631272.1631550 conf/mm/2009 db/conf/mm/mm2009.html#BollHLJKX09