Cita APA (7a ed.)

Martell, J. (1980). The twentieth-century world (3. ed.). Harrap.

Cita Chicago Style (17a ed.)

Martell, John. The Twentieth-century World. 3. ed. London: Harrap, 1980.

Cita MLA (9a ed.)

Martell, John. The Twentieth-century World. 3. ed. Harrap, 1980.