Logic: A Very Short Introduction (Very Short Introductions)

Category Theory in Context (Aurora: Dover Modern Math Originals)

Gödel's Proof

Language, Proof and Logic, 2nd Edition

Lectures on the Philosophy of Mathematics

Tough Riddles for Smart Kids: 500 Riddles and Brain Teasers that Will Challenge the Whole Family

Logic For Dummies

The Annotated Gödel: A Reader's Guide to his Classic Paper on Logic and Incompleteness

Mastering Logical Fallacies: The Definitive Guide to Flawless Rhetoric and Bulletproof Logic

Hard Logic Puzzles & Brain Games for Adults: 500 Puzzles & 12 Puzzle Types (Sudoku, Fillomino, Battleships, Calcudoku, Binary Puzzle, Slitherlink, ... (Challenging Fun Brain Teasers Series)