References
- FarnelL G. C. and Jenkins. R. L., J. photogr. Sci., 29, 39 (1981)
- Karnell. G. C. in The Theory of the Photographic Process (T. H. James. Edk 3rd ed. Macmillan. New York (1966). p. 83.
- Threadgold, S. D. IXe Congrès Intern de Photographie Scientifique et Appliquèe. Paris. 1935. Editions Rev. d’Optique. 1936.
- Farnell. G. C. J. photogr. Sci., 2, 145 (1954).
- Farnell, G. C, Saunders, A. E. and Solman, L. R., J. photogr. Sci., 21, 93, 118(1973).