Alvarez, A.; Pen-Yu, K.; and Vazquez, L. "The Numerical Study of a Nonlinear One-Dimensional Dirac Equation." Appl. Math. Comput. 18, 1-15, 1983.
Berestetskii, V. B.; Lifshitz, E. M.; and Ditaevskii, L. P. Quantum Electrodynamics, 2nd ed. Oxford, England: Pergamon Press, 1982.
Bethe, H. A. and Salpeter, E. Quantum Mechanics of One- and Two-Electron Atoms. New York: Plenum, p. 37, 1977.
Bjorken, J. D. and Drell, S. D. "The Dirac Equation." §1.3 in Relativistic Quantum Mechanics. New York: McGraw-Hill, pp. 6-9, 1964.
Dirac, P. A. M. "The Quantum Theory of the Electron." Proc. Roy. Soc. London A117, 610-624, 1928.
Dirac, P. A. M. "The Quantum Theory of the Electron, Part II." Proc. Roy. Soc. London A118, 351-361, 1928.
Dirac, P. A. M. Principles of Quantum Mechanics, 4th ed. Oxford, England: Oxford University Press, 1982.
Griffiths, D. J. "The Dirac Equation" and "Solutions to the Dirac Equation." §7.1-7.2 in Introduction to Elementary Particles. New York: Wiley, pp. 213-222, 1987.
Zwillinger, D. Handbook of Differential Equations, 3rd ed. Boston, MA: Academic Press, p. 137, 1997.