The late James Stewart received his M.S. from Stanford University and his Ph.D. from the University of Toronto.

He did research at the University of London and was influenced by the famous mathematician George Polya at Stanford University. Stewart was most recently Professor of Mathematics at McMaster University, and his research field was harmonic analysis.

Stewart was the author of a best-selling calculus textbook series published by Cengage Learning, including Calculus, Calculus: Early Transcendentals, and Calculus: Concepts and Contexts, as well as a series of precalculus texts.

London-based Helena Smith has been walking on the hygge side of life as a freelance travel writer and photographer for the last 15 years. One of her first assignments was to travel around Denmark, and she still returns regularly to enjoy saunas – alternating with icy lake plunges – healthy smorrebrod, impeccable Scandi design aesthetics and a population that is considered to be the happiest in the world.

Helena has written about Copenhagen for Lonely Planet, Rough Guides and Bradt, and she also has her own London food blog, eathackney.com. Happiest herself when cycling, swimming, looking at art and browsing a flea market, Helena wholeheartedly gives Copenhagen her vote.