add (c) symbol
diff --git a/Doc/copyright.tex b/Doc/copyright.tex
index d870d3c..465ca28 100644
--- a/Doc/copyright.tex
+++ b/Doc/copyright.tex
@@ -1,5 +1,5 @@
-Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
-The Netherlands.
+Copyright \copyright\ 1991-1995 by Stichting Mathematisch Centrum,
+Amsterdam, The Netherlands.
\begin{center}
All Rights Reserved
diff --git a/Doc/texinputs/copyright.tex b/Doc/texinputs/copyright.tex
index d870d3c..465ca28 100644
--- a/Doc/texinputs/copyright.tex
+++ b/Doc/texinputs/copyright.tex
@@ -1,5 +1,5 @@
-Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
-The Netherlands.
+Copyright \copyright\ 1991-1995 by Stichting Mathematisch Centrum,
+Amsterdam, The Netherlands.
\begin{center}
All Rights Reserved