Georg Gottlob Alexander Leitsch Daniele Mundici Computational Logic and Proof Theory, 5th Kurt Gödel Colloquium, KGC'97, Vienna, Austria, August 25-29, 1997, Proceedings Kurt Gödel Colloquium Lecture Notes in Computer Science 1289 Springer 1997 3-540-63385-5 db/conf/kgc/kgc97.html