--- a/src/Doc/Sugar/document/root.bib	Wed Jul 18 12:21:55 2018 +0200
+++ b/src/Doc/Sugar/document/root.bib	Wed Jul 18 16:44:01 2018 +0200
@@ -8,5 +8,5 @@
 
 @misc{tar,author={Gerwin Klein and Norber Schirmer and Tobias Nipkow},
 title={{LaTeX} sugar theories and support files}, 
-note={\url{http://isabelle.in.tum.de/sugar.tar.gz}}}
+note={\url{https://isabelle.in.tum.de/sugar.tar.gz}}}