1. Über die Eigengravitation des elektrischen Feldes nach der Einsteinschen Theorie;Reissner;Ann. Phys., Lpz.,1916
2. On the energy of the gravitational field in Einstein’s theory;Nordström;Proc. Kon. Ned. Akad. Wet.,1918
3. Proceedings of GR5;Bardeen,1968
4. Regular black hole in general relativity coupled to nonlinear electrodynamics;Ayón-Beato;Phys. Rev. Lett.,1998
5. New regular black hole solution from nonlinear electrodynamics;Ayon-Beato;Phys. Lett. B,1999