Qining Wang Yan Huang Guangming Xie Long Wang Let Robots Play Soccer under More Natural Conditions: Experience-Based Collaborative Localization in Four-Legged League. 353-360 2007 RoboCup http://dx.doi.org/10.1007/978-3-540-68847-1_35 conf/robocup/2007 db/conf/robocup/robocup2007.html#WangHXW07