1. Asada, H., and Brady, M. 1986. The curvature primal sketch. IEEE Trans. Patt. Anal. Mach. Intell., PAMI 8: 2?14.
2. Ballard, D.H. 1981. Generalizing the Hough transform to detect arbitrary shapes. Patt. Recog., 13(2): 111?122.
3. Barrett, E.B., Payton, P., and Brill, M.H. 1991. Contributions to the theory of projective invariants for curves in two and three dimensions. Proc. DARPA/ESPRIT Workshop on Invariants in Vision, Reykjavik, Iceland, March.
4. Bruckstein, A.M., Holt, R.J., Netravali, A.N., and Richardson, T.J. 1991. Invariant signatures for planar shape recognition under partial occlusion, AT&T Bell Labs Tech. Memo, Murray Hill, NJ, October.
5. Bruckstein, A.M., and Netravali, A.N. 1990. On differential invariants of planar curves and recognizing partially occluded planar shapes. AT&T Bell Laboratories Tech. Memo, Murray-Hill, NJ, July; also in Proc. Workshop on Visual Form, Capri, May, 1991.