This is a great book on mathematical puzzles in the vein of Martin Gardner's books, but with increasingly more involved and sophisticated problems; it is my fav

This is a great book on mathematical puzzles in the vein of Martin Gardner's books, but with increasingly more involved and sophisticated problems; it is my favorite puzzle book. If you know of other books of this style (apart from Gardner's), do share; especially if they involve lots of visual-mechanic reasoning in addition to logic. I am pitching the idea of a Greek translation to relevant parties, since most Greek kids and many teenagers lack the command of English (or Russian) to read the existing versions.