1. A.W. Thomas, W. Weise, Structure of the Nucleon (Wiley, Berlin, 2001)
2. B. Thaller, The Dirac Equation (Springer, New York, 1992)
3. T.Y. Wu, W.Y.P. Hwang, Relativistic Quantum Mechanics and Quantum Fields (World Scientific, Singapore, 1991)
4. W. Greiner, Relativistic Quantum Mechanics: Wave Equations (Springer, Berlin, 2000)
5. L.D. Landau, E.M. Lifshitz, Quantum Mechanics (Non-relativistic theory), Course of Theoretical Physics, vol. 3 (Elsevier, Amsterdam, 1977)