@book{4016,
	author = {Das, B. C. and Mukherjee, B. N. },
	title = {Differential calculus /},
	publisher = {U. N. DHUR & Sons Private Ltd.,},
	year = {c1949.[Reprinted 2006].},
	address = {New Delhi :},
	edition = {50th ed.},
	note = {Includes index.}
}