Exploiting capability constraints to solve global two-dimensional path planning problems. - R. F. Richbourg; Neil C. Rowe; Michael Zyda (ICRA, 1986)

Solving global two-dimensional routing problems using snell's law and a search. - R. F. Richbourg; Neil C. Rowe; Michael Zyda; Robert B. McGhee (ICRA, 1987)

An Efficient Snell's Law Method for Optimal-Path Planning across Multiple Two-Dimensional, Irregular, Homogeneous-Cost Regions. - Neil C. Rowe; R. F. Richbourg (Int. J. Robotics Res., 1990)