APA (7th ed.) Citation

Zhou, W., Sornette, D., Hill, R., & Dunbar, R. (2005). Discrete hierarchical organization of social group sizes.

Chicago Style (17th ed.) Citation

Zhou, W., D. Sornette, R. Hill, and R. Dunbar. Discrete Hierarchical Organization of Social Group Sizes. 2005.

MLA (9th ed.) Citation

Zhou, W., et al. Discrete Hierarchical Organization of Social Group Sizes. 2005.