Cita APA (7th ed.)

U.S. Geological Survey. Mineral industry surveys , copper in april 2006.

Cita Chicago (17th ed.)

U.S. Geological Survey. Mineral Industry Surveys , Copper in April 2006.

Cita MLA (9th ed.)

U.S. Geological Survey. Mineral Industry Surveys , Copper in April 2006.

Atenció: Aquestes cites poden no estar 100% correctes.