diff --git a/batch tests/test.txt b/batch tests/test.txt
index 0d2253f..927822e 100644
--- a/batch tests/test.txt	
+++ b/batch tests/test.txt	
@@ -2,6 +2,11 @@
 
 @setlocal
 
+@rem    Copyright 2017 by Jasper Paulsen.
+@rem    This batch script contains snippets of code from
+@rem    Tim Hill's book on Windows NT Shell Scripting,
+@rem    which is copyright 1998 by New Riders Publishing.
+
 @rem    This batch script assumes that it is in a folder
 @rem    (such as ~\bvt\40xx command line) that contains:
 @rem    A *.exe of the version of CAL being tested, named cal-40xx.exe