@book{37501,
	author = {Ferrer Beltr�an, Jordi.},
	title = {The logic of legal requirements},
	publisher = {Oxford University Press,},
	year = {2013.},
	address = {Oxford :},
	url = {http://dx.doi.org/10.1093/acprof:oso/9780199661640.001.0001}
}