1. F. Hargreaves and R. J. Hill: Journal Institute of Metals, 1929, vol. 41, p. 257.
2. J. M. Burgers: Proceedings Koninklijke Nederlandse Akademie van Wetenschappen, 1939, vol. 42, p. 293.
3. W. Shockley and W. T. Read: Physical Review, 1950, vol. 78, p. 275.
4. K. T. Aust and B. Chalmers: Proceedings Royal Soc., London, 1950, vol. A204, p. 359.
5. J. Washburn and E. R. Parker: AIME Trans., 1952, vol. 194, p. 1076; Journal of Metals, January 1952.