diff --git a/README.md b/README.md
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+++ b/README.md
@@ -186,7 +186,7 @@ Table of Contents
 - [Fundamentals of Database Systems - IIT Kanpur](https://nptel.ac.in/courses/106104135/)
 - [Principles of Database Management, Bart Baesens](https://www.youtube.com/playlist?list=PLdQddgMBv5zEhlpqdiUcf9aTNEtmESgyl)
 - [FIT9003 Database Systems Design - Monash University](https://itunes.apple.com/us/podcast/fit9003-database-systems-design/id306569364)
-- [15-445 - Introduction to Database Systems, CMU](https://15445.courses.cs.cmu.edu/fall2018/) ([YouTube-2018](https://www.youtube.com/playlist?list=PLSE8ODhjZXja3hgmuwhf89qboV1kOxMx7), [YouTube-2017](https://www.youtube.com/playlist?list=PLSE8ODhjZXjYutVzTeAds8xUt1rcmyT7x), [YouTube-2019](https://www.youtube.com/playlist?list=PLSE8ODhjZXjbohkNBWQs_otTrBTrjyohi))
+- [15-445 - Introduction to Database Systems, CMU](https://15445.courses.cs.cmu.edu/fall2018/) ([YouTube-2018](https://www.youtube.com/playlist?list=PLSE8ODhjZXja3hgmuwhf89qboV1kOxMx7), [YouTube-2017](https://www.youtube.com/playlist?list=PLSE8ODhjZXjYutVzTeAds8xUt1rcmyT7x), [YouTube-2019](https://www.youtube.com/playlist?list=PLSE8ODhjZXjbohkNBWQs_otTrBTrjyohi), [YouTube-2021](https://www.youtube.com/playlist?list=PLSE8ODhjZXjZaHA6QcxDfJ0SIWBzQFKEG))
 - [15-721 - Database Systems, CMU](http://15721.courses.cs.cmu.edu/spring2017) ([YouTube-2017](https://www.youtube.com/playlist?list=PLSE8ODhjZXjYgTIlqf4Dy9KQpQ7kn1Tl0), [YouTube-2016](https://www.youtube.com/playlist?list=PLSE8ODhjZXjbisIGOepfnlbfxeH7TW-8O))
 - [15-721 Advanced Database Systems (Spring 2019) - CMU](https://www.youtube.com/playlist?list=PLSE8ODhjZXja7K1hjZ01UTVDnGQdx5v5U)
 - [CS122 - Relational Database System Implementation, Winter 2014-2015 - Caltech](http://users.cms.caltech.edu/~donnie/cs122/)