Present State of the Surface Potential Measurements by Kelvin Force Microscopy. Atomic-scale Potential Imaging by Ultrahigh Vacuum Scanning Probe Microscopy.
4) T. Hochwitz, A.K. Henning, C. Levey, C. Daghlian, J. Slinkman, J.Never, P. Kaszuba, R. Gluck, R. Wells, J. Pekarik and R. Finch: J. Vac. Sci. Technol. B 14, 440 (1996).