diff --git a/R/argo.R b/R/argo.R
index e69ffa1bfd..1ad8a498c0 100644
--- a/R/argo.R
+++ b/R/argo.R
@@ -548,9 +548,12 @@ argoDecodeFlags <- function(f) # local function
 #' @references
 #' 1. \url{http://www.argo.ucsd.edu/}
 #' 
-#' 2. \url{http://archimer.ifremer.fr/doc/00187/29825/40575.pdf} documents the codes used in the netCDF files.
+#' 2. \samp{http://archimer.ifremer.fr/doc/00187/29825/40575.pdf}
+#' (link last checked 2016-06-18)
+#' documents the codes used in the netCDF files.
 #'
-#' 3. \url{http://www.argodatamgt.org/content/download/4729/34634/file/argo-dm-user-manual-version-2.3.pdf}
+#' 3. \samp{http://www.argodatamgt.org/content/download/4729/34634/file/argo-dm-user-manual-version-2.3.pdf}
+#' (link last checked 2016-06-18)
 #' is the main document describing argo data.
 #' 
 #' @section Data sources:
diff --git a/man/read.argo.Rd b/man/read.argo.Rd
index 0424c71400..f04796d5e0 100644
--- a/man/read.argo.Rd
+++ b/man/read.argo.Rd
@@ -157,9 +157,12 @@ Dan Kelley
 \references{
 1. \url{http://www.argo.ucsd.edu/}
 
-2. \url{http://archimer.ifremer.fr/doc/00187/29825/40575.pdf} documents the codes used in the netCDF files.
+2. \samp{http://archimer.ifremer.fr/doc/00187/29825/40575.pdf}
+(link last checked 2016-06-18)
+documents the codes used in the netCDF files.
 
-3. \url{http://www.argodatamgt.org/content/download/4729/34634/file/argo-dm-user-manual-version-2.3.pdf}
+3. \samp{http://www.argodatamgt.org/content/download/4729/34634/file/argo-dm-user-manual-version-2.3.pdf}
+(link last checked 2016-06-18)
 is the main document describing argo data.
 }
 \seealso{