1. New multifocal intraocular lens design;Hansen;J Cataract Refract Surg,1990
2. Early experience with the diffractive bifocal lens;Percival;Eur J Implant Refract Surg,1989
3. Bifokale Intraokularlinsen nach Kataraktextraktion - eigene Erfahrungen, Europaische Multizentrische Studie and FDA-Studie;Jacobi,1990
4. Contrast sensitivity in patients with a new type of multifocal intraocular lens;Olsen;J Cataract Refract Surg,1990
5. The design of a new letter chart for measuring contrast sensitivity;Pelli;Clin Vis Sci,1988