APA (7th ed.) Citation

Britton, J., Pavord, I., Wong, C., & Tattersfields, A. (1991). Beta 2-agonists in asthma.

Chicago Style (17th ed.) Citation

Britton, J., I. Pavord, C. Wong, and A. Tattersfields. Beta 2-agonists in Asthma. 1991.

MLA (9th ed.) Citation

Britton, J., et al. Beta 2-agonists in Asthma. 1991.