1. Solving the find-path problem by good representation of free space
2. CROWLEY , J. L. , 1984 , Navigation for an intelligent mobile robot . The First Conference on Artificial Intelligence Applications , I.E.E.E. Computer Society , Denver , Colorado , pp. 57 .
3. MORAVEC , M. , 1981 , Rover visual obstacle avoidance . Proceedings of the Seventh International Joint Conference on Artificial Intelligence .