Laaksonen, Maarit A., Esa Virtala, Paul Knekt, Hannu Oja, and Tommi Härkänen. 2011. “SAS Macros for Calculation of Population Attributable Fraction in a Cohort Study Design”. Journal of Statistical Software 43 (7):1-25. https://doi.org/10.18637/jss.v043.i07.