1. These Standard Reference Materials are available from the Office of Standard Reference Materials, National Bureau of Standards, Washington, D. C. 20234.
2. J. F. Nye, Physical Properties of Crystals — Their Representation by Tensors and Matrices. Oxford University Press, New York, 1957.
3. T. A. Hahn, J. Appl. Phys. 41, 5096 (1970).
4. B. D. Rothrock and R. K. Kirby, J. Research Natl. Bur. Standards 71C, 85 (1967).
5. G. W. Burns and W. S. Hurst, NASA Report CR-72884, 1972.