Di Piazza, Antonino Division Prof. Dr. Christoph H. Keitel, MPI for Nuclear Physics, Max Planck Society;
http://dx.doi.org/10.1103/PhysRevA.85.042107 (Supplementary material)
Di Piazza, A., & Milstein, A. I. (2012). Angular distribution of high-energy e+e− photoproduction close to the end of the spectrum at large momentum transfer. Physical Review. A, 85(4): 042107. doi:10.1103/PhysRevA.85.042107.