1. See, for example, Stevens, G. W. W., Microphotography- Photography and Photofabrication at Extreme Resolution, 2nd Edn., Chapman and Hall, London, 1968, p. 349.
2. Ref. 2, p. 216.
3. Ref. 2, Fig. 9, p. 27.
4. Ref. 2, p. 25.
5. Fritz, G. W., and Lavato, A., Kodak Photoresist Seminar Proceedings-1968 Edition, Vol. 1, p. 39.