Relativistic

An Introduction to the Lorentz-Dirac Equation - Notes by Eric Poisson providing two derivations of the Lorentz--Dirac equation.
arxiv.org/abs/gr-qc/9912045

Publications in Physics and Mathematics by Walter Pfeifer - A textbook for relativistic quantum mechanics with detailed description of the Dirac equation and other publications.
www.walterpfeifer.ch/

The Quantum Theory of Particles - A new approach to relativity, quantum mechanics, and field theory which solves many old puzzles, such as ultraviolet infinities and superluminal spreading of wave packets.
www.geocities.com/meopemuk/

Relativistic quantum mechanics - An electronic textbook for relativistic quantum mechanics is presented. It can be ordered free
rel.qm.walterpfeifer.ch

Selected Papers on Geometric Algebra in Quantum Mechanics - These papers analyze the quantum mechanical Dirac theory of the electron with respect to its geometric structure as revealed by reformulation in terms of Spacetime Algebra
modelingnts.la.asu.edu/html/GAinQM.html