APA (7th ed.) Citation

Wiking, M. (2019). The key to happiness: How to find purpose by unlocking the secrets of the world's happiest people. Penguin Life.

Chicago Style (17th ed.) Citation

Wiking, Meik. The Key to Happiness: How to Find Purpose by Unlocking the Secrets of the World's Happiest People. UK: Penguin Life, 2019.

MLA (9th ed.) Citation

Wiking, Meik. The Key to Happiness: How to Find Purpose by Unlocking the Secrets of the World's Happiest People. Penguin Life, 2019.