Wenping Wang Yi-King Choi Bin Chan Myung-Soo Kim Jiaye Wang Efficient Collision Detection for Moving Ellipsoids Using Separating Planes. 235-246 2004 72 Computing 1-2 http://www.springerlink.com/index/10.1007/s00607-003-0060-0 db/journals/computing/computing72.html#WangCCKW04