diff --git a/docs/index.md b/docs/index.md
index 091438f4540480dd5695ef585f935e9f13505dce..a9fb8e89a772353d1b83f7947c562838ab3a3109 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -12,6 +12,7 @@ There are many [tools](./tools.md) that adopted and integrated pairwise testing
 
 ### Links
 * [Pairwise testing tools](./tools.md)
+* [Comparison of tools efficiency](./efficiency.md)
 * [PICT Pairwise Test Generation tool](https://github.com/microsoft/pict)
 * [About this site](./about.md)