available in PDF (页面存档备份,存于互联网档案馆). M. Gellman and F. E. Low. Quantum Electrodynamics at Small Distances (PDF). (原始内容存档 (PDF)于2018-07-24). Mehra, Jagdish;
1007/978-94-010-2274-3_8. Greiner, Walter; Müller, B.; Rafelski, J. Quantum Electrodynamics of Strong Fields* With an Introduction into Modern Relativistic Quantum