diff -r cf3e57e6fec7 -r 6705725c0f1a handouts/ho01.tex
--- a/handouts/ho01.tex	Tue Sep 25 20:50:42 2018 +0100
+++ b/handouts/ho01.tex	Tue Sep 25 21:57:14 2018 +0100
@@ -257,7 +257,7 @@
 worse.\footnote{In this example Ruby uses the slightly different
   regular expression \texttt{a?a?a?...a?a?aaa...aa}, where the
   \texttt{a?} and \texttt{a} each occur $n$ times. More such test
-  cases can be found at \url{http://www.computerbytesman.com/redos/}.}
+  cases can be found at \url{https://www.owasp.org/index.php/Regular_expression_Denial_of_Service_-_ReDoS}.}
 Admittedly, these regular expressions are carefully chosen to exhibit
 this exponential behaviour, but similar ones occur more often than one
 wants in ``real life''. For example, on 20 July 2016 a similar regular