1. Impossible objects as nonsense sentences;Huffman,1971
2. Interpreting pictures of polyhedral scenes;Mackworth;Artificial Intelligence,1973
3. Curvature and creases: a primer on paper;Huffman,1975
4. Obtaining shape from shading information;Horn,1975
5. A photometric investigation of the slopes and heights of the ranges of hills in the maria of the moon;Van Diggelen;Bull. Astron. Inst. Netherlands,1951