http://www.crs.gov
http://www.bls.gov
http://www.federalreserve.gov/newsevents/speech/bernanke20120326a.htm
http://finance.fortune.cnn.com/2012/03/16/okuns-law/
http://www.bea.gov
http://libertystreeteconomics.newyorkfed.org/2012/03/okuns-law-and-longexpansions.html