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"
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: