APA (7th ed.) Citation

Appleby, P., Thorogood, M., Mann, J., & Key, T. (1999). The Oxford Vegetarian Study: An overview.

Chicago Style (17th ed.) Citation

Appleby, P., M. Thorogood, J. Mann, and T. Key. The Oxford Vegetarian Study: An Overview. 1999.

MLA (9th ed.) Citation

Appleby, P., et al. The Oxford Vegetarian Study: An Overview. 1999.