Kerr, W. C., Ye, Y., Subbaraman, M. S., Williams, E., & Greenfield, T. K. (2018). Changes in Marijuana Use Across the 2012 Washington State Recreational Legalization: Is Retrospective Assessment of Use Before Legalization More Accurate? J Stud Alcohol Drugs.

Kerr, William C., Yu Ye, Meenakshi Sabina Subbaraman, Edwina Williams, et Thomas K. Greenfield. "Changes in Marijuana Use Across the 2012 Washington State Recreational Legalization: Is Retrospective Assessment of Use Before Legalization More Accurate?" J Stud Alcohol Drugs 2018.

Kerr, William C., et al. "Changes in Marijuana Use Across the 2012 Washington State Recreational Legalization: Is Retrospective Assessment of Use Before Legalization More Accurate?" J Stud Alcohol Drugs 2018.