1. Tree and Pyramid Structures for Coding Hexagonally Sampled Binary Images;Burt,1979
2. Hexagonal parallel pattern transformations;Golay;IEEE Trans. Comput.,1969
3. A multiplication in N-space;Lucas,1979
4. A System for Hierarchical Addressing in Euclidean Space;Lucas,1980
5. Levels of Representation in Cultural Feature Extraction;Rosenfeld,1979