diff --git a/doc/references.bib b/doc/references.bib
index 691e2b6..ee89d10 100644
--- a/doc/references.bib
+++ b/doc/references.bib
@@ -56,6 +56,7 @@
   school = {Humboldt-Universität zu Berlin},
   year = {2012},
   type = {Diplomarbeit},
+  url = {https://sar.informatik.hu-berlin.de/research/publications/SAR-PR-2012-05/SAR-PR-2012-05_.pdf},
 }
 
 @UNPUBLISHED{linuxtag,