I found a reference that might be useful to include in the documentation

[timhuff]

The reference is Geometric Algebra for Electrical and Electronic Engineers.
It discusses the application of GA in terms of Maxwell's equations but gives a very good introduction to GA, in general. As its subtitle indicates: "This tutorial paper provides a short introduction to geometric algebra, starting with its history and then presenting its benefits and exploring its applications"

I find Figure 4 to be particularly useful: