APA (7th ed.) Citation

Watt, D. C., Brown, N., & Spencer, F. (1967). A history of the world in the twentieth century. Hodder & Stoughton.

Chicago Style (17th ed.) Citation

Watt, Donald Cameron, Neville Brown, and Frank Spencer. A History of the World in the Twentieth Century. [London]: Hodder & Stoughton, 1967.

MLA (9th ed.) Citation

Watt, Donald Cameron, et al. A History of the World in the Twentieth Century. Hodder & Stoughton, 1967.