@book{20,
	author = {Wood, Derek, and Dempster, Derek D.},
	title = {The narrow margin : the Battle of Britain and the rise of air power, 1930-40 /},
	publisher = {Pen & Sword Aviation,},
	year = {2010.},
	address = {Barnsley, South Yorkshire :},
	note = {Originally published: London : Hutchinson & Co., 1961.},
	url = {http://www.loc.gov/catdir/toc/fy12pdf02/2010549116.html}
}