1. Sievert, R., Acta Radiol., 17, 299 (1936).
2. von Ardenne, M., Naturwiss., 27, 485 (1939).
3. Cosslett, V. E., “The Electron Microscope”, pp. 72, 116 (Sigma Press, London, 1947).
4. See Crowther, J. A., “Handbook of Industrial Radiology”, pp. 151–182 (Institute of Physics, London, 1946); and Engström, A., “Progress in Biophysics”, pp. 164–196 (Butterworth, London, 1950).
5. Goldsztaub, S., C.R. Acad. Sci., Paris, 224, 458 (1947).