Where I can, I have put links to Amazon for books that are relevant to
the subject, click on the appropriate country flag to get more details
of the book or to buy it from them.
New Foundations for Classical Mechanics (Fundamental Theories of Physics). This
is very good on the geometric interpretation of this algebra. It has lots of insights
into the mechanics of solid bodies. I still cant work out if the position, velocity,
etc. of solid bodies can be represented by a 3D multivector or if 4 or 5D multivectors
are required to represent translation and rotation.