--- a/sets/quickref.tex	Wed Dec 01 16:51:35 2010 +0530
+++ b/sets/quickref.tex	Thu Dec 02 14:43:42 2010 +0530
@@ -9,7 +9,7 @@
 
 Other operations available:\\
 
-\begin{lstlising}
+\begin{lstlisting}
 \item "\&" -- Intersection
 \item "-" -- Difference
 \item "\^" -- Symmetric Difference