Scherr, S. J. (1999). Soil degradation: A threat to developing-country food security by 2020? International Food Policy Research Institute.
Citazione stile Chigago Style (17a edizione)Scherr, Sara J. Soil Degradation: A Threat to Developing-country Food Security by 2020? Washington, D.C: International Food Policy Research Institute, 1999.
Citatione MLA (9a ed.)Scherr, Sara J. Soil Degradation: A Threat to Developing-country Food Security by 2020? International Food Policy Research Institute, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.