ACM: Theory of computation~Proof theory

AMS: Mathematical logic and foundations / Proof theory and constructive mathematics

by Christoph Benzmüller, David Fuenmayor, Alexander Steen and Geoff Sutcliffe

by Asta Halkjær From and Frederik Krogsdal Jacobsen

by Andrei Popescu and Dmitriy Traytel

by Andrei Popescu and Dmitriy Traytel