CMU DB 2016 lectures for reference.

README.md

@@ -180,7 +180,7 @@ Courses
 - [Fundamentals of Database Systems - IIT Kanpur](http://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)
-- [15-721 - Database Systems, CMU](http://15721.courses.cs.cmu.edu/spring2017) ([Lectures - YouTube](https://www.youtube.com/playlist?list=PLSE8ODhjZXjYgTIlqf4Dy9KQpQ7kn1Tl0))
+- [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))
 - [CS122 - Relational Database System Implementation, Winter 2014-2015 - Caltech](http://users.cms.caltech.edu/~donnie/cs122/)
 - [CS 186 - Database Systems, UC Berkeley, Spring 2015](https://sites.google.com/site/cs186spring2015/home/schedule-and-notes) ([Lectures- YouTube](https://www.youtube.com/playlist?list=PL-XXv-cvA_iBVK2QzAV-R7NMA1ZkaiR2y))
 - [CS 6530 - Graduate-level Database Systems, Fall 2016, University of Utah](https://www.cs.utah.edu/~lifeifei/cs6530/) ([Lectures - YouTube](https://www.youtube.com/playlist?list=PLbuogVdPnkCqwHUcieMrytP453Ep0y6eI))