National Planning Institute. (2007). The virtual water concept. National Planning Institute.
Citazione stile Chigago Style (17a edizione)National Planning Institute. The Virtual Water Concept. cairo.: National Planning Institute, 2007.
Citatione MLA (9a ed.)National Planning Institute. The Virtual Water Concept. National Planning Institute, 2007.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.