diff --git a/courses/free-courses-en.md b/courses/free-courses-en.md
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--- a/courses/free-courses-en.md
+++ b/courses/free-courses-en.md
@@ -154,10 +154,10 @@
 * [Algorithms and Data Structures Tutorial - Full Course for Beginners](https://www.youtube.com/watch?v=8hly31xKli0) - Pasan Premaratne, Jay McGavren (freeCodeCamp)
 * [Analysis of Algorithms (CSE 373)](https://www3.cs.stonybrook.edu/~skiena/373/videos) - Steven Skiena
 * [Berkeley University CS 61B: Data Structures](http://datastructur.es/sp16/)
-* [Berkeley's CS 61B: Data Structures](https://archive.org/details/ucberkeley_webcast_QMV45tHCYNI)
 * [C Programming & Data Structures](https://www.youtube.com/playlist?list=PLBlnK6fEyqRhX6r2uhhlubuF5QextdCSM) - Neso Academy
 * [Codechef Solutions](https://www.youtube.com/playlist?list=PLRKOqqzwh75huOam-77G1v9uHjO9WWBRX) - Endeavour Monk
 * [Computer Sc - Programming and Data Structure](https://www.youtube.com/playlist?list=PLD9781AC5EBC9FA16) - P.P. Chakraborty
+* [CS Tutorials](https://www.youtube.com/playlist?list=PL9xmBV_5YoZPKwb4XPB1sG7S6kNpN9JJo) - Michael Sambol
 * [Data Structure and Algorithm](https://www.youtube.com/playlist?list=PLLvKknWU7N4y_eGpQdg1Y-hORO7cxtoLU) - Lalit Vashistha
 * [Data Structures](https://www.youtube.com/playlist?list=PL2_aWCzGMAwI3W_JlcBbtYTwiQSsOTa6P) - mycodeschool
 * [Data Structures](https://stepik.org/course/579/syllabus) - Niema Moshiri, Liz Izhikevich (Stepik)
@@ -187,7 +187,7 @@
 * [Learn DS and Algorithms](https://www.programiz.com/dsa) - Programiz
 * [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 (Fall 2011)](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-006-introduction-to-algorithms-fall-2011/)
+* [MIT's Introduction to Algorithms (Fall 2011)](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-006-introduction-to-algorithms-fall-2011/) - MIT
 * [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
 * [MIT's Introduction to Algorithms (Spring 2020)](https://ocw.mit.edu/courses/6-006-introduction-to-algorithms-spring-2020/) - Erik Demaine, Jason Ku, Justin Solomon
 * [Online Java + DSA + Interview preparation course](https://www.youtube.com/playlist?list=PL9gnSGHSqcnr_DxHsP7AW9ftq0AtAyYqJ) - Kunal Kushwaha
@@ -984,9 +984,9 @@
 * [Learn Java Programming - Java for Testers and Developers](https://www.udemy.com/course/learn-java-programming-a/) - Pavan Kumar (Udemy)
 * [Most Asked Core Java Frequently Asked Questions](https://www.youtube.com/playlist?list=PLyHJZXNdCXscoyL5XEZoHHZ86_6h3GWE1) - Code Decode
 * [Object Oriented Programming (OOP) In Java Course](https://www.youtube.com/playlist?list=PL9gnSGHSqcno1G3XjUbwzXHL8_EttOuKk) - Kunal Kushwaha
-* [Object-Oriented programming with Java, part I](https://moocfi.github.io/courses/2013/programming-part-1/)
-* [Object-Oriented programming with Java, part II](https://moocfi.github.io/courses/2013/programming-part-2/)
-* [Princeton Algorithms, Part 1](https://www.coursera.org/course/algs4partI)
+* [Object-Oriented programming with Java, part I](https://moocfi.github.io/courses/2013/programming-part-1/) - University of Helsinki
+* [Object-Oriented programming with Java, part II](https://moocfi.github.io/courses/2013/programming-part-2/) - University of Helsinki
+* [RestFul Web Service in Java](https://www.youtube.com/playlist?list=PLsyeobzWxl7oz8yL16PqO1sy9sxdlTuI1) - Telusko (Majrul Ansari, Navin Reddy)
 * [Servlet & JSP Tutorial Full Course](https://www.youtube.com/watch?v=OuBUUkQfBYM) - Telusko (Navin Reddy)
 * [Software Construction in Java](https://openlearninglibrary.mit.edu/courses/course-v1:MITx+6.005.1x+3T2016/about) - MIT Open Learning Library
 * [Spring 5 Core - An Ultimate Guide](https://www.udemy.com/learn-spring-5-core-from-scratch/) - Somnath Musib (Udemy)