(1982) The Lady or the Tiger? ISBN 0812921178 – ladies, tigers, and more logic puzzles (1982) Alice in Puzzle-Land ISBN 0688007481 (1985) To Mock a Mockingbird ISBN 0192801422 – puzzles based on combinatory logic (1987) Forever Undecided ISBN 0192801414 – puzzles based on undecidability in formal systems (1992) Satan, Cantor and Infinity ISBN 0679406883 (1997) The Riddle of Scheherazade ISBN 0156006065 (2007) The Magic Garden of George B. And Other Logic Puzzles ISBN 9788876990663, Polimetrica (Monza/Italy) (2009) Logical Labyrinths ISBN 9781568814438, A K Peters (2010) King Arthur in Search of his Dog ISBN 0486474356 (2013) The Godelian Puzzle Book: Puzzles, Paradoxes and Proofs ISBN 0486497054 (2015) The Magic Garden of George B and Other Logic Puzzles ISBN 978-981-4675-05-5