hartwick, J. M. (1989). Non-Renewable resources extraction programs and markets. Harwood academic Pub.
Chicago-stil citathartwick, John M. Non-Renewable Resources Extraction Programs and Markets. Chur: Harwood academic Pub, 1989.
MLA-referenshartwick, John M. Non-Renewable Resources Extraction Programs and Markets. Harwood academic Pub, 1989.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.