1. Bragg, W. H., Phil. Trans. Roy. Soc., A, 215, 253 (1915).
2. Robertson, J., J. Chem. Soc., 615 (1935); 1195 (1936).
3. Bokhoven, C., Schoone, J. C., and Bijvoet, J. M., Atca Cryst., 4, 275 (1951).
4. Smits, D. W., and Wiebenga, E. H., Acta Cryst., 6, 531 (1953).
5. von Laue, M., Ann. Physik, 50, 33 (1916). Coster, D., Knol, K. S., and Prins, J., Z. Phys., 63, 345 (1930). See also James, K. W., “The Optical Principles of the Diffraction of X-rays”, Chapter 4 (1948).