diff --git a/plan.txt b/plan.txt
index 5269ea5..0f57b74 100644
--- a/plan.txt
+++ b/plan.txt
@@ -156,14 +156,15 @@ Arrays
         * - size() - number of items
         * - capacity() - number of items it can hold
         * - is_empty()
-        - at(index) - returns item at given index, blows up if index out of bounds
-        - append(item) - or push(item) - check size of element 2^
-        - insert(index, item)
-        - prepend(item) - can use insert above at index 0
-        - delete(index)
-        - remove(item)
-        - find(item)
-        - resize(new_capacity) // private function
+        * - at(index) - returns item at given index, blows up if index out of bounds
+        * - append(item) - or push(item) - check size of element 2^
+        * - insert(index, item)
+        * - prepend(item) - can use insert above at index 0
+        * - pop() - remove from end, return value
+        - delete(index) - delete item at index, shifting all trailing elements left
+        - remove(item) - looks for value and removes index holding it (even if in multiple places)
+        - find(item) - looks for value and returns first index with that value
+        * - resize(new_capacity) // private function
             - when you reach capacity, resize to double the size
             - when popping an item, if size is 1/4 of capacity, resize to half
     - Time
@@ -334,6 +335,8 @@ Processes, Threads, Concurrency issues
 Process resource needs
 Thread resource needs
 Modern concurrency constructs with multicore processors
+Operating Systems:
+    - https://www.youtube.com/watch?v=-KWd_eQYLwY&index=2&list=PL-XXv-cvA_iBDyz-ba4yDskqMDY6A1w_c
 Context switching
     - How context switching is initiated by the operating system and underlying hardware
 Scheduling