B. A. Kordemskiĭ

Boris A. Kordemsky, a Russian teacher and popularizer of recreational mathematics, is probably the best-selling author of non-word puzzle books in the history of the world. Just one of his books, Matematicheskaya Smekalka (or, Mathematical Quick-Wits), sold more than a million copies in the Soviet Union/Russia alone, and it has been translated into many languages. By exciting millions of people in mathematical problems over five decades, he influenced generations of [puzzle] solvers both at home and abroad. -- Will Shortz & Serhiy Grabarchuk @ ageofpuzzles.com