diff --git a/README.md b/README.md
index 69caf2c..8ad0ebf 100644
--- a/README.md
+++ b/README.md
@@ -156,6 +156,8 @@ For instance, take into account the snaptshot above. If you already know how to
         * [Courated List of the 10 best free resources](https://medium.freecodecamp.org/these-are-the-best-free-courses-to-learn-data-structures-and-algorithms-in-depth-4d52f0d6b35a) 📰 🆓
          * Locks
            * [Let's talk locks! - Kavya Joshi](https://www.youtube.com/watch?v=tjpncm3xTTc) 📼 🆓
+         * Futex
+         * Semaphores
          * Alternative Data Structures
            * [“Esoteric Data Structures and Where to Find Them” - Allan Deutsch](https://www.youtube.com/watch?v=-8UZhDjgeZU) 📼 🆓
                 * 0:36 Slot map
diff --git a/resources/topic-graph.mmd b/resources/topic-graph.mmd
index c3db52f..d4e396d 100644
--- a/resources/topic-graph.mmd
+++ b/resources/topic-graph.mmd
@@ -27,9 +27,11 @@ graph TD
       ALG --> CPX[Complexity]
     PT --> DS[Data Scructures]
       DS --> Lock[Lock]
+      DS --> Futex[Futex]
+      DS --> Semaphore
       DS --> Graph[Graph]
       DS --> T3[Tree]
-      DS --> HS[Hash]
+      DS --> HS[HashMap/Table]
 
     SW --> DB[Databases]
       DB --> DBT[Theory]
diff --git a/resources/topic-graph.png b/resources/topic-graph.png
index bfebea1..c2bd0b9 100644
Binary files a/resources/topic-graph.png and b/resources/topic-graph.png differ