Não informado. (1968). Commodity trade and price trends. International Bank for Reconstruction and Development.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Commodity Trade and Price Trends. Washington: International Bank for Reconstruction and Development, 1968.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Commodity Trade and Price Trends. International Bank for Reconstruction and Development, 1968.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.