@book{1920,
	author = {Art, Robert J. and Jervis, Robert,},
	title = {International politics},
	publisher = {Pearson,},
	year = {2015.},
	address = {Boston :},
	edition = {Twelfth edition.},
	url = {http://www.vlebooks.com/vleweb/product/openreader?id=Exeter&isbn=9781292070889}
}