1. Solving the find-path problem by good representation of free space
2. Chien, Y.R., Koivo, A.J. and Lee, B.H. 1988. On-line generation of collision free trajectories. Proceedings 1988 IEEE International Conference on Robotics and Automation. 1988. pp.209–214.
3. Connolly, C.I., Burns, J.B. and Weiss, R. 1990. Path planning using Laplace's equation. Proceedings 1990 IEEE International Conference on Robotics and Automation. 1990. pp.2102–2106.
4. Real-Time Pathfinding in Multirobot Systems Including Obstacle Avoidance