doc-src/IsarRef/Thy/document/Inner_Syntax.tex

--- a/doc-src/IsarRef/Thy/document/Inner_Syntax.tex	Sat Feb 04 14:20:39 2012 +0100
+++ b/doc-src/IsarRef/Thy/document/Inner_Syntax.tex	Sat Feb 04 14:25:14 2012 +0100
@@ -561,7 +561,7 @@
   line break; the entire phrase is a pretty printing block.
 
   The general idea of pretty printing with blocks and breaks is also
-  described in \cite{paulson-ml2}.%
+  described in \cite{paulson-ml2}; it goes back to \cite{Oppen:1980}.%
 \end{isamarkuptext}%
 \isamarkuptrue%
 %