1. T. Pavlidis: Structural pattern recognition. Springer Verlag, Berlin, 1977
2. A. Rosenfeld: Picture processing: 1976 Computer Graphics and Image Processing 6, 157–183, 1977
3. R. O. Duda, P.E. Hart: Pattern classification and scene analysis. J. Wiley, New York, 1972
4. H. Niemann: Methoden der Mustererkennung. Akademische Verlagsgesellschaft, Frankfurt, 1974
5. A. Rosenfeld (ed.): Digital picture analysis. Springer Verlag, Berlin, 1976