APA-referens (7:e uppl.)

Irwin, D. A. (2000). Could the U.S. iron industry have survived free trade after the civil war? National Bureau of Economic Research.

Chicago-referens (17:e uppl.)

Irwin, Douglas A. Could the U.S. Iron Industry Have Survived Free Trade After the Civil War? Cambridge: National Bureau of Economic Research, 2000.

MLA-referens (9:e uppl.)

Irwin, Douglas A. Could the U.S. Iron Industry Have Survived Free Trade After the Civil War? National Bureau of Economic Research, 2000.