diff --git a/lisp/language/cyrillic.el b/lisp/language/cyrillic.el
index 094885a5054..037869b6886 100644
--- a/lisp/language/cyrillic.el
+++ b/lisp/language/cyrillic.el
@@ -24,8 +24,9 @@
 
 ;;; Commentary:
 
-;; The character set ISO8859-5 is supported.  KOI-8 and ALTERNATIVNYJ
-;; are converted to ISO8859-5 internally.
+;; The character set ISO8859-5 is supported.  See
+;; http://www.ecma.ch/ecma1/STAND/ECMA-113.HTM.  KOI-8 and
+;; ALTERNATIVNYJ are converted to ISO8859-5 internally.
 
 ;;; Code:
 
diff --git a/lisp/language/hebrew.el b/lisp/language/hebrew.el
index f182e7cffa8..ec3edfce127 100644
--- a/lisp/language/hebrew.el
+++ b/lisp/language/hebrew.el
@@ -25,6 +25,7 @@
 ;;; Commentary:
 
 ;; For Hebrew, the character sets ISO8859-8 is supported.
+;; See http://www.ecma.ch/ecma1/STAND/ECMA-121.HTM.
 
 ;;; Code: