Guangyu Zhu Ming Yang Kai Yu Wei Xu Yihong Gong Detecting video events based on action recognition in complex scenes using spatio-temporal descriptor. 165-174 2009 ACM Multimedia http://doi.acm.org/10.1145/1631272.1631297 conf/mm/2009 db/conf/mm/mm2009.html#ZhuYYXG09