1. Refraction under cyclodamia;Smith;Am. J. Ophth.,1926
2. Stigmatoscopy;Lancaster;Tr. Am. Ophth. Soc.,1934
3. The Leland refractor;van Wien;Arch. Ophth.,1940
4. Comparison of a new sensitometric method with usual technics of refraction;Luckiesh;Arch. Ophth.,1943
5. Copeland, J.: Riggs' Optical Developments, March, 1937.