diff --git a/network-services-pentesting/pentesting-voip/README.md b/network-services-pentesting/pentesting-voip/README.md
index bbdbb52a..3ae1e81a 100644
--- a/network-services-pentesting/pentesting-voip/README.md
+++ b/network-services-pentesting/pentesting-voip/README.md
@@ -557,6 +557,7 @@ The easiest way to install a software such as Asterisk is to download an **OS di
 ## References
 
 * [https://github.com/Pepelux/sippts/wiki](https://github.com/Pepelux/sippts/wiki)
+* [http://blog.pepelux.org/](http://blog.pepelux.org/)
 * [https://www.rtpbleed.com/](https://www.rtpbleed.com/)
 * [https://medium.com/vartai-security/practical-voip-penetration-testing-a1791602e1b4](https://medium.com/vartai-security/practical-voip-penetration-testing-a1791602e1b4)