Cita APA (7a ed.)

Saffer, H., Terry-McElrath, Y., & Wakefield, M. (2007). The Effect of Nicotine Replacement Therapy Advertising on Youth Smoking. National Bureau of Economic Research.

Cita Chicago Style (17a ed.)

Saffer, Henry, Yvonne Terry-McElrath, y Melanie Wakefield. The Effect of Nicotine Replacement Therapy Advertising on Youth Smoking. National Bureau of Economic Research, 2007.

Cita MLA (9a ed.)

Saffer, Henry, et al. The Effect of Nicotine Replacement Therapy Advertising on Youth Smoking. National Bureau of Economic Research, 2007.