"NIOSH- Agriculture". United States National Institute for Occupational Safety and Health. 11 Mayıs 2016 tarihinde kaynağından arşivlendi. Erişim tarihi: 10 Ekim 2007.
Bai, Z.G., D.L. Dent, L. Olsson, and M.E. Schaepman. 2008. Global assessment of land degradation and improvement 1:identification by remote sensing. Report 2008/01, FAO/ISRIC - Rome/Wageningen. Retrieved on December 5, 2008 from "Land degredation on the rise" 12 Şubat 2009 tarihinde Wayback Machine sitesinde arşivlendi.
"NIOSH- Agriculture". United States National Institute for Occupational Safety and Health. 11 Mayıs 2016 tarihinde kaynağından arşivlendi. Erişim tarihi: 10 Ekim 2007.
Bai, Z.G., D.L. Dent, L. Olsson, and M.E. Schaepman. 2008. Global assessment of land degradation and improvement 1:identification by remote sensing. Report 2008/01, FAO/ISRIC - Rome/Wageningen. Retrieved on December 5, 2008 from "Land degredation on the rise" 12 Şubat 2009 tarihinde Wayback Machine sitesinde arşivlendi.