APA

Martell J., . (1980). The Twentieth-Century World. London: Harrap Limited.

Chicago

Martell John, . 1980. The Twentieth-Century World. London: Harrap Limited.

Harvard

Martell J., . (1980). The Twentieth-Century World. London: Harrap Limited.

MLA

Martell John, . The Twentieth-Century World. London: Harrap Limited. 1980.