@article{Porto:2013TA, author = "Porto, Stefano and Hartin, Anthony and Moortgat-Pick, Gudrid", title = "{Methods for evaluating physical processes in strong external fields at e+e? colliders: Furry picture and quasi-classical approach}", doi = "10.22323/1.177.0039", journal = "PoS", year = 2013, volume = "Corfu2012", pages = "039" }