APA (7th ed.) Citation

Barrow, J. D. (1991). Theories of everything: The quest for ultimate explanation.

Chicago Style (17th ed.) Citation

Barrow, John D. Theories of Everything: The Quest for Ultimate Explanation. Oxford [England] (Clarendon Press), 1991.

MLA (8th ed.) Citation

Barrow, John D. Theories of Everything: The Quest for Ultimate Explanation. 1991.