David Glover has worked as a research scientist and as a teacher of math and science. He has written bestselling math and science books for all ages, from elementary schoolchildren to university students. He loves challenging puzzles and problems! Diego Vaisberg, DGPH art director, working as a designer and illustrator. Also working in product and design department for Ink-co kids accessories brand, and professor since 2014 at Editorial design and Illustration at the Palermo University, Buenos Aires.