@book{13756,
	author = {Rovelli, Carlo,},
	title = {Quantum gravity /},
	publisher = {Cambridge University Press,},
	year = {2004.},
	series = {Cambridge monographs on mathematical physics},
	address = {Cambridge, UK ;},
	url = {http://www.loc.gov/catdir/toc/cam041/2004045497.html}
}