References
- Yule, J. A. C and Nielsen, W. J., Modern Lithgraphy. 19. (9) 1951.
- Yulc, J. A. C., Proceedinns of Fifth Internationl Conference Of Printing Research Institutes, 1959.
- Harrison, V. G. W., Mitchener, G. A. and Lawion, L. E. J. Phot, Science. Vol. 3, 1955.