References
- Tritton, F. J., Wilson, E. T., Phot. J., 79, 396,(1939).
- Gresham, D. C, Phot. J., 92B 91, (1952).
- Audus, S. R., Process Engravers Monthly, 55, 236, (1948)
- Haigh, A. Cartwright, H. M., Process Engravers Monthly. 54, 50, (1947).
- Cackett, F. G. S., Penrose Annual. 44, 112, (1950).
- Poulton, J., Brit. & Col. Printer. 1952, July 25, 86.
- Clapper, F. R., Technical Association of the Graphic Arts, 5th Annual Conference Report, 1953.