411 REFERENCE · Wikibooks
Physics Using Geometric Algebra/Relativistic Classical Mechanics/References
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Some sources of other information
The web site of William E. Baylis has some extended information on the notation used.
In particular, Relativity in Introductory Physics explains in more detail some of the notation used in this wikibook.