1. Relaxation and constrained optimization by local processes;Ullman;Computer Graphics Image Processing,1979
2. The Theory of Splines and Their Applications;Ahlberg,1967
3. Machine contouring using minimum curvature;Briggs;Geophysics,1974
4. Computing shape using a theory of human stereo vision;Grimson,1980
5. Orientation and Form;Rock,1973