David Chaum. Numbers Can Be a Better Form of Cash than Paper. In Bart Preneel, René Govaerts, Joos Vandewalle, editors, Computer Security and Industrial Cryptography - State of the Art and Evolution, ESAT Course, Leuven, Belgium, May 21-23, 1991. Volume 741 of Lecture Notes in Computer Science, pages 174-178, Springer, 1991.
Abstract is missing.