Xiaofeng Tong Tao Wang Wenlong Li Yimin Zhang Bo Yang Fei Wang Lifeng Sun Shiqiang Yang A Three-Level Scheme for Real-Time Ball Tracking. 161-171 2007 conf/mcam/2007 MCAM http://dx.doi.org/10.1007/978-3-540-73417-8_23 db/conf/mcam/mcam2007.html#TongWLZYWSY07