Keitel, Christoph H. Division Prof. Dr. Christoph H. Keitel, MPI for Nuclear Physics, Max Planck Society;
http://link.aps.org/doi/10.1103/PhysRevA.53.543 (Verlagsversion)
Petch, J. C., Keitel, C. H., Knight, P. L., & Marangos, J. P. (1996). Role of electromagnetically induced transparency in resonant four-wave-mixing schemes. Physical Review. A, 53(1), 543-561. doi:10.1103/PhysRevA.53.543.