1. Anzai, S., “Reflection type Image Forming Optical System Having a Large Angle of View,” U.S. Patent No. 4,037,943 (July 26, 1977).
2. “Third Order Aberrations in Cassegrain-Type Telescopes and Coma Correction in Servo-Stabilized Images,”;Bottema;Appl. Opt.,1971
3. “Reflecting Microscopes,”;Burch;Proc. Phys. Soc.,1947
4. “Unettes et Telescopes,”;Danjon,1935
5. “Telescopes and Accessories,”;Dimitroff,1945