diff --git a/R/karate.R b/R/karate.R
index a4c1962..8395582 100644
--- a/R/karate.R
+++ b/R/karate.R
@@ -56,7 +56,7 @@
 #' @references
 #'   Wayne W. Zachary. An Information Flow Model for Conflict and Fission
 #'   in Small Groups. *Journal of Anthropological Research* Vol. 33,
-#'   No. 4 452-473
+#'   No. 4 452-473 \doi{10.1086/jar.33.4.3629752}
 #' @source
 #'   See reference below.
 #' @keywords datasets
diff --git a/man/karate.Rd b/man/karate.Rd
index 0d2c757..0c4dcf6 100644
--- a/man/karate.Rd
+++ b/man/karate.Rd
@@ -60,6 +60,6 @@ A.'s faction but chose Mr. Hi's club.
 \references{
 Wayne W. Zachary. An Information Flow Model for Conflict and Fission
 in Small Groups. \emph{Journal of Anthropological Research} Vol. 33,
-No. 4 452-473
+No. 4 452-473 \doi{10.1086/jar.33.4.3629752}
 }
 \keyword{datasets}