@book{6568,
	author = {Mahmud, Sultan. and Hossain, Syed Quasim, },
	title = {A text book on higher trigonometry /},
	publisher = {East Bengal Pub.,},
	year = {1964.},
	address = {Dhaka, Bangladesh :},
	edition = {2nd rev. ed.},
	note = {For B A & B Sc. Pass and Honours Students.}
}