1. Barrett, C. S., Structure of Metals, 414 (McGraw-Hill, 1952).
2. Taylor, A., X-ray Metallography, 757 (J. Wiley, 1961).
3. Johnston, J., J. Amer. Chem. Soc., 36, 16 (1914).
4. Lewis, D., and Pearson, H., Nature, 196, 162 (1962).
5. Hedin, R., Swedish Cement and Concrete Res., Inst. Proc., No. 33 (1962).