S. J. Zilker, S. Schloter, A. Leopold, M. Grasruck, A. Schreiber, J. Pan, U. Hofmann, and D. Haarer, "Photoelectric properties of organic photorefractive glasses: Charge transport and its relation to the holographic response,"
in Advances in Photorefractive Materials, Effects and Devices, P. Andersen, P. Johansen, H. Pedersen, P. Petersen, and M. Saffman, eds.,
Vol. 27 of Trends in Optics and Photonics
(Optical Society of America, 1999), paper OPM3.