@book{3987,
	author = {Subrahmanyam, N. and Lal, Brij V.},
	title = {A Textbook of Optics /},
	publisher = {S Chand,},
	year = {2019.},
	address = {New Delhi :},
	edition = {25th Rev. ed.},
	note = {Includes index.}
}