"This book can serve as a delightful guide to advanced calculus, giving firm foundations to further studies." -Acta Sci. Math "An inviting, unusual, high-level introduction to vector calculus, based solidly on differential forms. Superb informal but sophisticated, down-to-earth but general, geometrically and physically intuitive but mathematically rigorous, entertaining but serious. Remarkably diverse applications, physical and mathematical." -The American Mathematical Monthly