(1961) Theory of Formal Systems ISBN 069108047X (1968) First-Order Logic ISBN 0486683702 (1992) Gödel's Incompleteness Theorems ISBN 0195046722 (1993) Recursion Theory for Metamathematics ISBN 019508232X (1994) Diagonalization and Self-Reference ISBN 0198534507 (1996) Set Theory and the Continuum Problem ISBN 0198523955 (2014) A Beginner's Guide to Mathematical Logic ISBN 0486492370 (2016) A Beginner's Further Guide to Mathematical Logic ISBN 978-981-4730-99-0