Georg Gottlob Alexander Leitsch Daniele Mundici Computational Logic and Proof Theory, Third Kurt Gödel Colloquium, KGC'93, Brno, Czech Republic, August 24-27, 1993, Proceedings Kurt Gödel Colloquium Lecture Notes in Computer Science 713 Springer 1993 3-540-57184-1 db/conf/kgc/kgc93.html