diff --git a/README.md b/README.md
index 17f2f64..aa3d690 100644
--- a/README.md
+++ b/README.md
@@ -238,8 +238,8 @@ Sometimes the classes are not in session so you have to wait a couple of months,
 - [ ] Prep Course:
     - [ ] [Software Engineer Interview Unleashed (paid course)](https://www.udemy.com/software-engineer-interview-unleashed):
         - Learn how to make yourself ready for software engineer interviews from a former Google interviewer.
-    - [ ] [Python for Data Structures, Algorithms, and Interviews! (paid course)](https://www.udemy.com/python-for-data-structures-algorithms-and-interviews/): 
-        - A Python centric interview prep course which covers data structures, algorithms, mock interviews and much more. 
+    - [ ] [Python for Data Structures, Algorithms, and Interviews! (paid course)](https://www.udemy.com/python-for-data-structures-algorithms-and-interviews/):
+        - A Python centric interview prep course which covers data structures, algorithms, mock interviews and much more.
 
 ## Pick One Language for the Interview
 
@@ -500,8 +500,8 @@ Write code on a whiteboard or paper, not a computer. Test with some sample input
 - [ ] [A Gentle Introduction to Algorithm Complexity Analysis](http://discrete.gr/complexity/)
 - [ ] [Orders of Growth (video)](https://class.coursera.org/algorithmicthink1-004/lecture/59)
 - [ ] [Asymptotics (video)](https://class.coursera.org/algorithmicthink1-004/lecture/61)
-- [ ] [UC Berkeley Big O (video)](https://youtu.be/VIS4YDpuP98)
-- [ ] [UC Berkeley Big Omega (video)](https://youtu.be/ca3e7UVmeUc)
+- [ ] ~~[UC Berkeley Big O (video)](https://youtu.be/VIS4YDpuP98)~~
+- [ ] ~~[UC Berkeley Big Omega (video)](https://youtu.be/ca3e7UVmeUc)~~
 - [ ] [Amortized Analysis (video)](https://www.youtube.com/watch?v=B3SpQZaAZP4&index=10&list=PL1BaGV1cIH4UhkL8a9bJGG356covJ76qN)
 - [ ] [Illustrating "Big O" (video)](https://class.coursera.org/algorithmicthink1-004/lecture/63)
 - [ ] TopCoder (includes recurrence relations and master theorem):
@@ -790,10 +790,10 @@ Write code on a whiteboard or paper, not a computer. Test with some sample input
     - [ ] [4. System Sorts](https://www.youtube.com/watch?v=rejpZ2htBjE&index=4&list=PLe-ggMe31CTeE3x2-nF1-toca1QpuXwE1)
 
 - [ ] UC Berkeley:
-    - [ ] [CS 61B Lecture 29: Sorting I (video)](https://www.youtube.com/watch?v=EiUvYS2DT6I&list=PL4BBB74C7D2A1049C&index=29)
-    - [ ] [CS 61B Lecture 30: Sorting II (video)](https://www.youtube.com/watch?v=2hTY3t80Qsk&list=PL4BBB74C7D2A1049C&index=30)
-    - [ ] [CS 61B Lecture 32: Sorting III (video)](https://www.youtube.com/watch?v=Y6LOLpxg6Dc&index=32&list=PL4BBB74C7D2A1049C)
-    - [ ] [CS 61B Lecture 33: Sorting V (video)](https://www.youtube.com/watch?v=qNMQ4ly43p4&index=33&list=PL4BBB74C7D2A1049C)
+    - [ ] [CS 61B Lecture 29: Sorting I (video)](https://archive.org/details/ucberkeley_webcast_EiUvYS2DT6I)
+    - [ ] [CS 61B Lecture 30: Sorting II (video)](https://archive.org/details/ucberkeley_webcast_2hTY3t80Qsk)
+    - [ ] [CS 61B Lecture 32: Sorting III (video)](https://archive.org/details/ucberkeley_webcast_Y6LOLpxg6Dc)
+    - [ ] [CS 61B Lecture 33: Sorting V (video)](https://archive.org/details/ucberkeley_webcast_qNMQ4ly43p4)
 
 - [ ] [Bubble Sort (video)](https://www.youtube.com/watch?v=P00xJgWzz2c&index=1&list=PL89B61F78B552C1AB)
 - [ ] [Analyzing Bubble Sort (video)](https://www.youtube.com/watch?v=ni_zk257Nqo&index=7&list=PL89B61F78B552C1AB)
@@ -1921,15 +1921,15 @@ Sit back and enjoy. "Netflix and skill" :P
 - [ ] CSE373 - Analysis of Algorithms (25 videos)
     - [Skiena lectures from Algorithm Design Manual](https://www.youtube.com/watch?v=ZFjhkohHdAA&list=PLOtl7M3yp-DV69F32zdK7YJcNXpTunF2b&index=1)
 
-- [ ] [UC Berkeley 61B (Spring 2014): Data Structures (25 videos)](https://www.youtube.com/watch?v=mFPmKGIrQs4&list=PL-XXv-cvA_iAlnI-BQr9hjqADPBtujFJd)
+- [ ] [UC Berkeley 61B (Spring 2014): Data Structures (25 videos)](https://archive.org/details/ucberkeley-webcast-PL-XXv-cvA_iAlnI-BQr9hjqADPBtujFJd)
 
-- [ ] [UC Berkeley 61B (Fall 2006): Data Structures (39 videos)](https://www.youtube.com/playlist?list=PL4BBB74C7D2A1049C)
+- [ ] [UC Berkeley 61B (Fall 2006): Data Structures (39 videos)](https://archive.org/details/ucberkeley-webcast-PL4BBB74C7D2A1049C)
 
-- [ ] [UC Berkeley 61C: Machine Structures (26 videos)](https://www.youtube.com/watch?v=gJJeUFyuvvg&list=PL-XXv-cvA_iCl2-D-FS5mk0jFF6cYSJs_)
+- [ ] [UC Berkeley 61C: Machine Structures (26 videos)](https://archive.org/details/ucberkeley-webcast-PL-XXv-cvA_iCl2-D-FS5mk0jFF6cYSJs_)
 
 - [ ] [OOSE: Software Dev Using UML and Java (21 videos)](https://www.youtube.com/playlist?list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO)
 
-- [ ] [UC Berkeley CS 152: Computer Architecture and Engineering (20 videos)](https://www.youtube.com/watch?v=UH0QYvtP7Rk&index=20&list=PLkFD6_40KJIwEiwQx1dACXwh-2Fuo32qr)
+- [ ] ~~[UC Berkeley CS 152: Computer Architecture and Engineering (20 videos)](https://www.youtube.com/watch?v=UH0QYvtP7Rk&index=20&list=PLkFD6_40KJIwEiwQx1dACXwh-2Fuo32qr)~~
 
 - [ ] [MIT 6.004: Computation Structures (49 videos)](https://www.youtube.com/playlist?list=PLrRW1w6CGAcXbMtDFj205vALOGmiRc82-)