1. Geometry, Particles, and Fields;Felsager,1998
2. Introduction to Electrodynamics;Griffiths,1999
3. An Elementary Primer for Gauge Theory;Moriyasu,1983
4. Introduction to Quantum Mechanics;Griffiths,2004
5. Schwinger's principle and gauge fixing in the free electromagnetic field;de Melo;Nuovo Cimento B,2006