Williams, G. C., McGregor, H., Sharp, D., Kouides, R. W., Lévesque, C. S., Ryan, R. M., & Deci, E. L. (2006). A Self-Determination Multiple Risk Intervention Trial to Improve Smokers' Health. Blackwell Science Inc.

Williams, Geoffrey C., Holly McGregor, Daryl Sharp, Ruth W. Kouides, Chantal S. Lévesque, Richard M. Ryan, and Edward L. Deci. A Self-Determination Multiple Risk Intervention Trial to Improve Smokers' Health. Blackwell Science Inc, 2006.

Williams, Geoffrey C., et al. A Self-Determination Multiple Risk Intervention Trial to Improve Smokers' Health. Blackwell Science Inc, 2006.