diff --git a/doc/src/z_references.bib b/doc/src/z_references.bib
index 68cdd5f76f9..91f96efa540 100644
--- a/doc/src/z_references.bib
+++ b/doc/src/z_references.bib
@@ -90,7 +90,7 @@ @techreport{betz_biased_global_routing_tech_report
     type = {CSRI Technical Report},
     number = {358},
     year = {1996},
-    url = {http://www.eecg.toronto.edu/~vaughn/ papers/techrep.ps.Z},
+    url = {http://www.eecg.toronto.edu/~vaughn/papers/techrep.pdf},
 }
 
 @inproceedings{betz_automatic_generation_of_fpga_routing,