References 

Bibliography

1. Malacara, Daniel. Geometrical and Instrumental Optics. Boston: Academic Press, 1988.
2. Smith, Warren. Modern Optical Engineering. Boston: McGraw Hill, 2008.
3. Ray Sidney, Applied Photograhic Optics London Focal 2002. 

Webliography 

4.en.wikipedia.org/wiki/Abbe_refractometer

5.www.fpharm.uniba.sk/fileadmin/user_upload/english/Fyzika/Refractive_index.pdf

6.www2.ups.edu/faculty/hanson/labtechniques/refractometry/theory.htm