@book{148860,
	author = {Ortín, Tomás, and ebrary, Inc.},
	title = {Gravity and strings},
	publisher = {Cambridge University Press,},
	year = {2004.},
	series = {Cambridge monographs on mathematical physics},
	address = {Cambridge :},
	url = {http://site.ebrary.com/lib/strathmore/Doc?id=10124667}
}