1. Impossible objects as nonsense sentences;Huffman,1971
2. On seeing things;Clowes;Artificial Intelligence,1971
3. Interpretation of imperfect line data as three-dimensional scene;Falk;Artificial Intelligence,1972
4. Turner KJ. Computer perception of curved objects using a television camera. PhD thesis, School of Artificial Intelligence, Edinburgh University, 1974.
5. Understanding line drawings of scenes with shadows;Waltz,1975