@article{MuellerPeitzRafelskietal.2006, author = {Berndt M{\"u}ller and Heinrich Peitz and Johann Rafelski and Walter Greiner}, title = {Solution of the Dirac equation for strong external fields}, journal = {Physical review letters}, volume = {28}, number = {19}, pages = {1235 -- 1238}, url = {http://link.aps.org/abstract/PRL/v28/p1235}, year = {2006}, }