@book{107036,
	author = {Piper, F. C. and Murphy, Sean,},
	title = {Cryptography :},
	publisher = {Oxford University Press,},
	year = {2002.},
	series = {Very short introductions ;},
	address = {Oxford ;},
	note = {Ejemplar incompleto faltan pag. 1-22},
	url = {http://www.loc.gov/catdir/enhancements/fy0614/2002510457-d.html}
}