1. Abraham R., and Shaw C. 1983. Dynamics-The Geometry of Behavior, pt. 3: Global Behavior. Aerial Press: Santa Cruz, CA.
2. Arnold V.I. 1973. Ordinary Differential Equations. MIT Press: Cambridge, MA.
3. Bruss A.R. 1982. The eikonal equation: some results applicable to computer vision. J. Math. Phys. 23(5): 890?896.
4. Elliot R.J. 1987. Viscosity Solutions and Optimal Control, Longman Scientific and Technical: New York.
5. Giblin, P., and Weiss, R. 1987. Reconstruction of surfaces from profiles. Proc. Intern. Conf. Comput. Vision, London, June 1987, pp. 136?144.