diff -r 340f130b3d38 -r 30b75b7958d6 src/Pure/PIDE/markup.ML
--- a/src/Pure/PIDE/markup.ML	Sun Oct 05 16:05:17 2014 +0200
+++ b/src/Pure/PIDE/markup.ML	Sun Oct 05 17:58:36 2014 +0200
@@ -55,7 +55,7 @@
   val position_properties: string list
   val positionN: string val position: T
   val expressionN: string val expression: T
-  val citationN: string val citation: T
+  val citationN: string val citation: string -> T
   val pathN: string val path: string -> T
   val urlN: string val url: string -> T
   val indentN: string
@@ -349,7 +349,7 @@
 
 (* citation *)
 
-val (citationN, citation) = markup_elem "citation";
+val (citationN, citation) = markup_string "citation" nameN;
 
 
 (* external resources *)