@article{IonescuReinhardtMuelleretal.2006,
  author    = {Dorin Cezar Ionescu and Joachim Reinhardt and Berndt M{\"u}ller and Walter Greiner and Gerhard Soff},
  title     = {Nonlinear extensions of the Dirac equation and their implications in QED},
  journal   = {Physical review A},
  volume    = {38},
  number    = {2},
  pages     = {616 -- 620},
  url       = {http://link.aps.org/abstract/PRA/v38/p616},
  year      = {2006},
}