diff --git a/R/data-bac.R b/R/data-bac.R
index 44a2b4d2..b4a0cce5 100644
--- a/R/data-bac.R
+++ b/R/data-bac.R
@@ -13,7 +13,8 @@
 #'   \item{bac}{a numeric vector}
 #'   }
 #' @source J. Malkevitch and L.M. Lesser. For All Practical Purposes:
-#' Mathematical Literacy in Today's World. WH Freeman & Co, 2008.
+#' Mathematical Literacy in Today's World. WH Freeman & Co, 2008.  The data
+#' origin is given in the [Electronic Encyclopedia of Statistical Examples and Exercises](https://bcs.whfreeman.com/WebPub/Statistics/shared_resources/EESEE/BloodAlcoholContent/index.html), 1992.
 #' @keywords datasets
 #' @examples
 #'