APA (7th ed.) Citation

Munroe, R. (2015). What if?: Serious scientific answers to absurd hypothetical questions (First published in paperback in 2015.). John Murray.

Chicago Style (17th ed.) Citation

Munroe, Randall. What If?: Serious Scientific Answers to Absurd Hypothetical Questions. First published in paperback in 2015. London: John Murray, 2015.

MLA (9th ed.) Citation

Munroe, Randall. What If?: Serious Scientific Answers to Absurd Hypothetical Questions. First published in paperback in 2015. John Murray, 2015.