APA (7th ed.) Citation

Helliwell, J. F., Layard, R., & Sachs, J. (2013). World happiness report 2013. Sustainable Development Solutions Network.

Chicago Style (17th ed.) Citation

Helliwell, John F., Richard Layard, and Jeffrey Sachs. World Happiness Report 2013. New York, N. Y: Sustainable Development Solutions Network, 2013.

MLA (9th ed.) Citation

Helliwell, John F., et al. World Happiness Report 2013. Sustainable Development Solutions Network, 2013.