diff --git a/src/content/posts/humanistic-psychology/index.md b/src/content/posts/humanistic-psychology/index.md
index e0de29e95..edd207e48 100644
--- a/src/content/posts/humanistic-psychology/index.md
+++ b/src/content/posts/humanistic-psychology/index.md
@@ -186,7 +186,8 @@ be more autonomous and creative work outcome that targets more on the _problems_
 ### Chapter 4 - Basic Needs: Just the Basic
 
 What we are talking about here is also called _Gratification Theory_ - gratifying a lower need bumps a person to the
-next level of need. The validity of this theory is justified given the following premises being true:
+next level of need. The [validity](https://youtu.be/NKEhdsnKKHs?t=411) of this theory is justified given the following
+premises being true:
 
 1. Frustration Theory
 2. Learning Theory