diff --git a/docs/mcv4u7.md b/docs/mcv4u7.md
index 20f8bc7..c4b7a3c 100644
--- a/docs/mcv4u7.md
+++ b/docs/mcv4u7.md
@@ -543,7 +543,7 @@ $$
\end{align*}
$$
-(Source: Kognity)
+(Source: Wikimedia)
The direction of the torque can be found using the **right-hand rule**.