Keep your brain healthy and active with The Great Book of Sudoku. According to the University of Edinburgh, UK, research has found that Sudoku puzzles can trigger "survival genes" in the brain that normally lay dormant and could reduce the chance of Dementia or Alzheimer\'s disease. With over 500 puzzles, this is the must-have companion for enjoying on your travels or on a dull rainy day. Product Information: • ISBN: 9781398804883 • Author: Eric Saunders • Publisher: Arcturus Publishing • Format: Paperback • Pages: 304 • Dimensions: 23.4 x 15.3 cm