In: Michael J. W. Chen (Hrsg.). Proceedings of OE'90. High-Speed Inspection Architectures, Barcoding, and Character Recognition, September 3, Boston, MA, USA, Pages 305-316, SPIE, Vol. 1384, No. 1, SPIE, 1991.
In: Proceedings of The International Conference on Document Analysis and Recognition. International Conference on Document Analysis and Recognition (ICDAR-91), September 30 - October 2, St. Malo, France, Pages 444-453, 9/1991.
In: Proceedings of the 6th International Conference on Visual Communication and Image Processing. Visual Communications and Image Processing (VCIP-91), 6th, Boston, MA, USA, Pages 20-30, SPIE, Vol. 1606, SPIE, 11/1991.
In: Proceedings of the 4th International Symposium on Artificial Intelligence. International Symposium on Artificial Intelligence (ISAI), 4th, November 13-15, Cancún, Mexico, Pages 314-320, AI Magazine, Vol. 13, No. 2, AAAI, 11/1991.
In: Harold Boley; M.M. Richter (Hrsg.). International Workshop on Processing Declarative Knowledge. International Workshop on Processing Declarative Knowledge (PDK-91), July 1-3, Kaiserslautern, Germany, Pages 161-170, Lecture Notes in Computer Science (LNCS), Springer, 1991.