APA (7th ed.) Citation

GF, A., DG, S., PS, H., S, K., & L, Z. (2004). Doughnut holes and price controls. Health Affairs, 23, W4.

Chicago Style (17th ed.) Citation

GF, Anderson, Shea DG, Hussey PS, Keyhani S, and Zephyrin L. "Doughnut Holes and Price Controls." Health Affairs 23 (2004): W4.

MLA (9th ed.) Citation

GF, Anderson, et al. "Doughnut Holes and Price Controls." Health Affairs, vol. 23, 2004, p. W4.