Bøker i Krazydad Tough Kakuro-serien

From the creator of the most popular free printable puzzle website on the Internet, Krazydad, here are 99 stupendously challenging 14x19 Kakuro puzzles for you to solve. Printed on a substance called paper, which can be used with a physical stylus called a pencil that leaves actual graphite marks and can be erased. Includes a pithy introduction and a remarkably clear and patient tutorial, just in case you need it.