Mathur Maya B, Ding Peng, Riddell Corinne A, VanderWeele Tyler J
Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA Quantitative Sciences Unit, Stanford University, Palo Alto, CA,
Epidemiology. 2018 Sep;29(5):e45-e47. doi: 10.1097/EDE.0000000000000864.