@book{61528,
	author = {Coleman, Jules L.},
	title = {Hart's postscript  essays on the postscript to The concept of law},
	publisher = {Oxford University Press},
	year = {2001},
	address = {Nueva York (Estados Unidos)},
	url = {http://www.loc.gov/catdir/enhancements/fy0612/2001021840-t.html}
}