APA (7th ed.) Citation

Ward, H. (1985). World powers in the Twentieth Century (2. ed.). British Broadcasting Corp.

Chicago Style (17th ed.) Citation

Ward, Harriet. World Powers in the Twentieth Century. 2. ed. London: British Broadcasting Corp, 1985.

MLA (9th ed.) Citation

Ward, Harriet. World Powers in the Twentieth Century. 2. ed. British Broadcasting Corp, 1985.