diff --git a/free-courses-en.md b/free-courses-en.md
index 8d1efd2ce2c68813a1dbf838b82acd489ff1a955..d1628760317ca5d42af882903cf8240c6d997a18 100644
--- a/free-courses-en.md
+++ b/free-courses-en.md
@@ -52,7 +52,9 @@
 
 * [Berkeley University CS 61B: Data Structures](http://datastructur.es/sp16/)
 * [IIT Bombay Foundation of Data Structures (CS213.1x)](https://courses.edx.org/courses/course-v1:IITBombayX+CS213.1x+1T2017/course/)
-* [Introduction to Algorithms (SMA 5503)](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-introduction-to-algorithms-sma-5503-fall-2005) - Charles Leiserson
+* [MIT's Design and Analysis of Algorithms (Spring 2012)](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-design-and-analysis-of-algorithms-spring-2012) - Dana Moshkovitz, Bruce Tidor
+* [MIT's Design and Analysis of Algorithms (Spring 2015)](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-design-and-analysis-of-algorithms-spring-2015) - Erik Demaine, Srini Devadas, Nancy Lynch
+* [MIT's Introduction to Algorithms (SMA 5503) (Fall 2005)](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-introduction-to-algorithms-sma-5503-fall-2005) - Charles Leiserson, Erik Demaine
 * [Princeton University Algorithms, Part 1](https://www.coursera.org/learn/algorithms-part1)
 * [Princeton University Algorithms, Part 2](https://www.coursera.org/learn/algorithms-part2)
 * [Stanford University Algorithms: Design and Analysis, Part 1](http://online.stanford.edu/course/algorithms-design-and-analysis-part-1)