Citazione APA

Keylor, W. R. (1992). The Twentieth century world: An international history (Ed.2.).

Stile di citazione Chicago

Keylor, William R. The Twentieth Century World: An International History. Ed.2. 1992.

Citazione MLA

Keylor, William R. The Twentieth Century World: An International History. Ed.2. 1992.