Smith D., Conway J.H. On Quaternions and Octonions

AK Peters, 2003,160 p. An investigation of the geometry of quaternion and octonion algebras, this book is intended for mathematicians, physicists, and crystallographers at any level - from undergraduate to professional - who are interested in the symmetries of low-dimensional space.
The book can also be used as a text for graduate courses in many mathematical fields, including geometry, group theory, algebra, and number theory.