Lichtheim, G. (1974). Imperialism. Penguin.
Cita Chicago (17th ed.)Lichtheim, George. Imperialism. Harmondsworth: Penguin, 1974.
Cita MLA (8th ed.)Lichtheim, George. Imperialism. Penguin, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.