1. BEA, 2002. Bureau of Economic Analysis: Gross State Product data. Available from: http://www.bea.doc.gov/bea/regional/gsp/.
2. BEA, 2003. Regional accounts: gross state product. Online Report. Available from: http://www.bea.doc.gov/bea/regional/docs/Regional_GSP.pdf.
3. Understanding the Scale and Resolution Effects in Remote Sensing and GIS;Cao,1997
4. Nighttime images of the Earth from space;Croft;Scientific American,1978
5. Real output decline in transition economies—forget GDP, try power consumption data!;Dobozi;Transition Newsletter,1995