X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fbasic.h;h=b3383250ff215991daf2152f09e59900ebb48153;hp=3ae3282c3e7ce32c8ba1b85adb37615ed845db03;hb=39eceef41403ae77569110626f1fc957243228b7;hpb=25b4d894b5b2f7f56fb49e62a7767ab969d5249f

diff --git a/ginac/basic.h b/ginac/basic.h
index 3ae3282c..b3383250 100644
--- a/ginac/basic.h
+++ b/ginac/basic.h
@@ -3,7 +3,7 @@
  *  Interface to GiNaC's ABC. */
 
 /*
- *  GiNaC Copyright (C) 1999-2016 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2018 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -92,7 +92,8 @@ struct map_function {
 
 /** Degenerate base class for visitors. basic and derivative classes
  *  support Robert C. Martin's Acyclic Visitor pattern (cf.
- *  http://objectmentor.com/publications/acv.pdf). */
+ *  http://condor.depaul.edu/dmumaugh/OOT/Design-Principles/acv.pdf
+ *  or chapter 10 of Andrei Alexandrescu's "Modern C++ Design"). */
 class visitor {
 protected:
 	virtual ~visitor() {}