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3. Milestones in Optical History (Rochester, NY: Bausch and Lomb, 1954).
4. I. Asimov, Biographical Encyclopedia of Science and Technology ( Garden City, NY: Doubleday, 1972 ).
5. D. J. Hamlin, “What a Spectacle! Eyeglasses and How They Evolved,” Smithsonian
13, 1983, 100–111.