1. Census of agriculture;[NASS] National Agricultural Statistics Service,1997
2. Nebraska Agricultural Statistics Service. 2002. 2002 Nebraska agricultural statistics annual bulletin—prices and economic data. Available at: http://www.nass.usda.gov/ne/2002book. Accessed 28 September 2004
3. Annual weather data for Nebraska;[NOAA] National Oceanic and Atmospheric Administration,2003
4. 2002 Nebraska farm custom rates—part I;Jose,2002
5. Nebraska Agri-Facts, Issue 22;Nebraska Agricultural Statistics Service,2002