David Norman. (1994). FAO farm systems management series N.7: Farming systems development and soil conservation. Rome: FAO.
Παραπομπή Chicago StyleDavid Norman. FAO Farm Systems Management Series N.7: Farming Systems Development and Soil Conservation. Rome: FAO, 1994.
Παραπομπή MLADavid Norman. FAO Farm Systems Management Series N.7: Farming Systems Development and Soil Conservation. Rome: FAO, 1994.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.