Não informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Natural Resources & Energy. New York: United Nations, Department of Technical Cooperation for Development.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.