1. http:nws.noaa.gov/oh/hic/flood_stats/flood_loss_time_series.shtml
2. Flood Damage in the United States,1926–2000: A Reanalysis of National Weather Service Estimates;Pielke,2002
3. Reanalysis of U.S. National Weather Service Flood Loss Database
4. Tracking Billion-Dollar U.S. Weather Disasters;Lott,2006
5. Observations: Surface and atmospheric climate change;Trenberth,2007