Otto
Books
Philosophy and Fun of Algebra
Prime Numbers
First Fifty Digits of Pi
Tangled Tale
Mathematical Problems
Short Account of the History of Mathematics
Fourth Dimension Simply Explained
Calculus Made Easy
Miscellanea Curiosa, Vol 1
Fourth Dimension
Passages from the Life of a Philosopher
Einstein Theory of Relativity
Foundations of Geometry
Science - History of the Universe Vol. 8: Mathematics
Introduction to the History of Science
Flatland: A Romance of Many Dimensions (version 3)
Letters on Different Subjects in Natural Philosophy, Volume 1 (Letters to a German Princess)
Use of Knowledge in Society
Ultimate Foundation of Economic Science