diff --git a/.gitignore b/.gitignore
index f422262d..2f4eb7a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ _minted-paper/
 result
 
 !report.pdf
+!references/*.pdf
diff --git a/references/2014_Building_a_Scalable_System_for_Stealthy_P2P-Botnet_Detection.pdf b/references/2014_Building_a_Scalable_System_for_Stealthy_P2P-Botnet_Detection.pdf
new file mode 100644
index 00000000..b0297fb2
Binary files /dev/null and b/references/2014_Building_a_Scalable_System_for_Stealthy_P2P-Botnet_Detection.pdf differ