KHURANA A., . (2001). THEORY AND PRACTICE OF OPTICS AND REFRACTION. NEW DELHI: ELSEVIER.
KHURANA A.K, . 2001. THEORY AND PRACTICE OF OPTICS AND REFRACTION. NEW DELHI: ELSEVIER.
KHURANA A.K, . THEORY AND PRACTICE OF OPTICS AND REFRACTION. NEW DELHI: ELSEVIER. 2001.