--- a/README	Sat Jan 27 00:28:27 2007 +0100
+++ b/README	Mon Jan 29 15:11:39 2007 +0100
@@ -1,7 +1,7 @@
 
 libtu
 
-Copyright (c) Tuomo Valkonen 1999-2004.
+Copyright (c) Tuomo Valkonen 1999-2007.
 <tuomov at iki.fi>
 
 
@@ -29,3 +29,5 @@
 system's versions of these functions, if available, modify
 system.mk.
 
+The implementation of red-black trees is based on that by
+James S. Plank; see README.rb for details.