J. Qi, W. Angerer, M. S. Yeganeh, A. G. Yodh, and W. M. Theis, "Charge Diffusion along GaAs(001) Surfaces measured by Spatially Separated Photoexciting and Second Harmonic Generating Beams,"
in International Quantum Electronics Conference, J. Shah, C. Weiman, R. Freman, and J. Fujimoto, eds.,
Vol. 9 of OSA Technical Digest
(Optical Society of America, 1994), paper QPD23.