Cita APA (7a ed.)

Childe, V. G., & Clark, G. (1942). What happened in history. Penguin books.

Cita Chicago Style (17a ed.)

Childe, V. Gordon, y Grahame Clark. What Happened in History. Baltimore: Penguin books, 1942.

Cita MLA (8a ed.)

Childe, V. Gordon, y Grahame Clark. What Happened in History. Penguin books, 1942.