1. A consistency technique for pattern association;Ullmann;Trans. IRE (IT),1962
2. On seeing things;Clowes;Artif. Intell.,1971
3. Impossible objects as nonsense sentences;Huffman,1971
4. Relaxation labeling and the reduction of local ambiguities;Zucker,1976
5. Contextual classification of multispectral pixel data;Kittler;Image Vision Comput.,1984