more explicit syntax, to avoid misunderstanding of foo-bar as 3 separate arguments;

--- a/src/Pure/Tools/bibtex.ML	Sun Oct 05 18:44:04 2014 +0200
+++ b/src/Pure/Tools/bibtex.ML	Sun Oct 05 22:18:40 2014 +0200
@@ -20,7 +20,7 @@
     Thy_Output.antiquotation @{binding cite}
       (Scan.lift
         (Scan.option (Parse.verbatim || Parse.cartouche) --
-         Scan.repeat1 (Parse.position Args.name)))
+         Parse.and_list1 (Parse.position Args.name)))
       (fn {context = ctxt, ...} => fn (opt, citations) =>
         let
           val _ =