Jicheng Liu Haibo Gao Zongquan Deng Jianguo Tao Effect of Slip on Tractive Performance of Small Rigid Wheel on Loose Sand. 1109-1116 2008 ICIRA (1) http://dx.doi.org/10.1007/978-3-540-88513-9_118 conf/icira/2008-1 db/conf/icira/icira2008-1.html#LiuGDT08