@book{69409,
	author = {Torretti, Roberto,},
	title = {Relatividad y espaciotiempo /},
	publisher = {RIL editores,},
	year = {2003.},
	address = {Providencia, Santiago de Chile:},
	url = {https://login.zproxy.cun.edu.co/login?url=https://www.digitaliapublishing.com/a/18595/}
}