books.google.com - Introduces puzzles and math problems involving coincidence, ciphers, games, the I Ching, geometric figures, and paradoxes....https://books.google.com/books/about/Knotted_Doughnuts_and_Other_Mathematical.html?id=LWbGQgAACAAJ&utm_source=gb-gplus-shareKnotted Doughnuts and Other Mathematical Entertainments
Martin Gardner is the author of more than seventy books on a vast range of topics including "Did Adam & Eve Have Navels?", "Calculus Made Easy", & "The Annotated Alice". He lives in Hendersonville, North Carolina.
Knotted Doughnuts and Other Mathematical Entertainments