If you enjoy playing around with quaternions, you may also have fun with geometric algebra. Geometric Algebra for Physicists is very clear and gently paced. ht

If you enjoy playing around with quaternions, you may also have fun with geometric algebra. Geometric Algebra for Physicists is very clear and gently paced. http://www.amazon.com/Geometric-Algebra-Physicists-Chris-Doran/dp/0521715954/ http://www.amazon.com/Geometric-Algebra-Physicists-Chris-Dor... This one also looks good: http://www.amazon.com/Linear-Geometric-Algebra-Alan-Macdonald/dp/1453854932/ http://www.amazon.com/Linear-Geometric-Algebra-Alan-Macdonal...