http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Instability in the terms of trade of primary commodities, 1900-1982
Food and Agriculture Organization of the United Nations
Pasquale L. Scandizzo and Dimitris Diakosawas.
FAO economic and social development paper ; 64