Gaya APA

Keirl, A. (2012). Clinical Optics and Refraction : A Guide for Optometrists, Contact Lens Opticians and Dispensing Opticians . Singapore: Elsevier Limited.

Gaya MLA

Keirl, Andrew. "Clinical Optics and Refraction : A Guide for Optometrists, Contact Lens Opticians and Dispensing Opticians". Singapore: Elsevier Limited, 2012. Text.