APA (7e ed.) Bronvermelding

Scherr, S. J. (1999). Soil degradation: A threat to developing-country food security by 2020? International Food Policy Research Institute.

Chicago (17e ed.) Bronvermelding

Scherr, Sara J. Soil Degradation: A Threat to Developing-country Food Security by 2020? Washington, D.C: International Food Policy Research Institute, 1999.

MLA (9e ed.) Bronvermelding

Scherr, Sara J. Soil Degradation: A Threat to Developing-country Food Security by 2020? International Food Policy Research Institute, 1999.