National Planning Institute. (2007). The virtual water concept. National Planning Institute.
Chicago-čujuhus (17. p.)National Planning Institute. The Virtual Water Concept. cairo.: National Planning Institute, 2007.
MLA-čujuhus (9. p.)National Planning Institute. The Virtual Water Concept. National Planning Institute, 2007.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.