APA (7th ed.) Citation

Niven, D. (2005). The 100 simple secrets of happy people: What scientists have learned and how you can use it. Capstone.

Chicago Style (17th ed.) Citation

Niven, David. The 100 Simple Secrets of Happy People: What Scientists Have Learned and How You Can Use It. London: Capstone, 2005.

MLA (9th ed.) Citation

Niven, David. The 100 Simple Secrets of Happy People: What Scientists Have Learned and How You Can Use It. Capstone, 2005.