The late Ken Russell was a UK IQ test expert who produced over sixty books covering all aspects of testing, crosswords, puzzles and reasoning, including Test Your IQ, in partnership with Philip Carter (all published by Kogan Page). Philip Carter is a UK IQ test expert who is continually devising new IQ tests and puzzles. He has produced many books covering all aspects of testing, puzzles and reasoning. These include Advanced IQ Tests, IQ and Personality Tests, IQ and Psychometric Test Workbook, IQ and Psychometric Tests, Test and Assess your Brain Quotient and The Brain Fitness Workout. With the late Ken Russell he has written Test your IQ, Test and Assess your IQ and Ultimate IQ, all published by Kogan Page.