diff --git a/unit04_public_key/lecture/README.MD b/unit04_public_key/lecture/README.MD
index 3a90baf..52f3f3c 100644
--- a/unit04_public_key/lecture/README.MD
+++ b/unit04_public_key/lecture/README.MD
@@ -17,8 +17,8 @@ The key concepts are: Basics, RSA, Elliptic Curve and ElGamal.
 
 ## Presentations
 
-* Week 4 Presentation (PDF) - Public Key Encryption: [here](https://github.com/billbuchanan/esecurity/blob/master/unit04_public_key/lecture/chapter04_public_msc.pdf).
-* Week 4 Presentation (video) - Public Key Encryption: [here](https://youtu.be/QEYqkxuzoTg).
+* Unit 4 Presentation (PDF) - Public Key Encryption: [here](https://github.com/billbuchanan/esecurity/blob/master/unit04_public_key/lecture/chapter04_public_msc.pdf).
+* Unit 4 Presentation (video) - Public Key Encryption: [here](https://youtu.be/qoRCL3qDnXE).
 
 ## Examples