diff --git a/README.md b/README.md
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@@ -1108,29 +1108,26 @@ You'll get more graph practice in Skiena's book (see Books section below) and th
     - [x] How to write tests: http://jasonpolites.github.io/tao-of-testing/ch4-1.1.html
 
 - [ ] **Design patterns**
-    - [ ] CS164 Lecture 3 Design Patterns: https://youtu.be/mym5m-GKG0Q?t=660
-    - [x] Chapter 6 (Part 1) - Patterns: https://youtu.be/LAP2A80Ajrg?list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO&t=3344
-    - [x] Chapter 6 (Part 2) - Abstraction-Occurrence, General Hierarchy, Player-Role, Singleton, Observer, Delegation: https://www.youtube.com/watch?v=U8-PGsjvZc4&index=12&list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO
-    - [x] Chapter 6 (Part 3) - Adapter, Facade, Immutable, Read-Only Interface, Proxy: https://www.youtube.com/watch?v=7sduBHuex4c&index=13&list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO
-    - description:
-        - https://www.lynda.com/Developer-Programming-Foundations-tutorials/Foundations-Programming-Design-Patterns/135365-2.html
-        - Patterns: https://www.youtube.com/playlist?list=PLF206E906175C7E07
-        - UML: https://www.youtube.com/playlist?list=PLGLfVvz_LVvQ5G-LdJ8RLqe-ndo7QITYc
-    - [ ] 101 Design Patterns & Tips for Developers: https://sourcemaking.com/design-patterns-and-tips
+    - [x] Quick UML review: https://www.youtube.com/watch?v=3cmzqZzwNDM&list=PLGLfVvz_LVvQ5G-LdJ8RLqe-ndo7QITYc&index=3
     - [ ] Learn these patterns:
         - [ ] strategy
-        - [ ] singleton
-        - [ ] adapter
+        - [x] singleton
+        - [x] adapter
         - [ ] prototype
         - [ ] decorator
         - [ ] visitor
-        - [ ] factory
+        - [x] factory
         - [ ] facade
         - [ ] observer
         - [ ] proxy
         - [ ] delegate
+    - [x] Chapter 6 (Part 1) - Patterns: https://youtu.be/LAP2A80Ajrg?list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO&t=3344
+    - [x] Chapter 6 (Part 2) - Abstraction-Occurrence, General Hierarchy, Player-Role, Singleton, Observer, Delegation: https://www.youtube.com/watch?v=U8-PGsjvZc4&index=12&list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO
+    - [x] Chapter 6 (Part 3) - Adapter, Facade, Immutable, Read-Only Interface, Proxy: https://www.youtube.com/watch?v=7sduBHuex4c&index=13&list=PLJ9pm_Rc9HesnkwKlal_buSIHA-jTZMpO
+    - [ ] Series of short videos (27 videos): https://www.youtube.com/playlist?list=PLF206E906175C7E07
     - [ ] Head First Design Patterns: https://www.amazon.com/Head-First-Design-Patterns-Freeman/dp/0596007124
         - I know the canonical book is "Design Patterns: Elements of Reusable Object-Oriented Software", but Head First is great for beginners to OO.
+    - [ ] Handy reference: 101 Design Patterns & Tips for Developers: https://sourcemaking.com/design-patterns-and-tips
 
 - [ ] **Scheduling**
     - in an OS, how it works