Gaya APA

Niven, D. (2000). The 100 Simple Secrets of Happy People: What Scientists Have Learned and How You Can Use It . San Francisco: HarperCollins.

Gaya MLA

Niven, David. "The 100 Simple Secrets of Happy People: What Scientists Have Learned and How You Can Use It". San Francisco: HarperCollins, 2000. Text.