Dr Gareth Moore is the author of a wide range of brain-training and puzzle books for both children and adults, including The Little Book of Puzzles, The Kids' Book of Crosswords, The Brain Workout, Train the Brain and a wide range of other books. He also writes the monthly magazine Sudoku Xtra and runs the puzzle website www.puzzlemix.com. He gained his Ph.D at the University of Cambridge, UK, where he worked on machine intelligence.