Can Mathematics Be Proved Consistent?: Gödel's Shorthand Notes & Lectures on Incompleteness

Saved from the Cellar: Gerhard Gentzen’s Shorthand Notes on Logic and Foundations of Mathematics

The Great Formal Machinery Works: Theories of Deduction and Computation at the Origins of the Digital Age

Elements of Logical Reasoning

Proof Analysis: A Contribution to Hilbert's Last Problem