1. A grammar for the topological analysis of plane figures;Buneman,1969
2. Perceptrons;Minsky,1969
3. Picture Processing by Computer;Rosenfeld,1969
4. Connectivity in digital pictures;Rosenfeld;J. Assoc. Comput. Mach.,1970
5. Arcs and curves in digital pictures;Rosenfeld;J. Assoc. Comput. Mach.,1973