Citazione Stile APA (7a Edizione)

Beckman, P. R. (1984). World politics in the twentieth century. Prentice-Hall.

Citazione stile Chigago Style (17a edizione)

Beckman, Peter R. World Politics in the Twentieth Century. Englewood Cliffs, New Jersey: Prentice-Hall, 1984.

Citatione MLA (9a ed.)

Beckman, Peter R. World Politics in the Twentieth Century. Prentice-Hall, 1984.