@book{207298,
	author = {Ayala, César J. and Bernabe Riefkohl, Rafael.},
	title = {Puerto Rico in the American century},
	publisher = {University of North Carolina Press},
	year = {2007.},
	address = {Chapel Hill},
	url = {http://www.loc.gov/catdir/toc/ecip075/2006039830.html}
}