diff --git a/subjects/btreeapplyinorder/README.md b/subjects/btreeapplyinorder/README.md
index ac93b868..4b4c99f1 100644
--- a/subjects/btreeapplyinorder/README.md
+++ b/subjects/btreeapplyinorder/README.md
@@ -2,7 +2,11 @@
 
 ### Instructions
 
-Write a function that applies a function in order to each element in the tree (see "in order tree walks").
+Write a function that applies a given function `f`, **in order**, to each element in the tree.
+
+### Notions
+
+- [Tree Traversal](https://en.wikipedia.org/wiki/Tree_traversal)
 
 ### Expected function
 
diff --git a/subjects/btreeapplypostorder/README.md b/subjects/btreeapplypostorder/README.md
index 80bf85b9..4c5f6121 100644
--- a/subjects/btreeapplypostorder/README.md
+++ b/subjects/btreeapplypostorder/README.md
@@ -2,7 +2,11 @@
 
 ### Instructions
 
-Write a function that applies a function using a postorder walk to each element in the tree.
+Write a function that applies a given function `f`, to each element in the tree using a postorder walk.
+
+### Notions
+
+- [Tree Traversal](https://en.wikipedia.org/wiki/Tree_traversal)
 
 ### Expected function
 
diff --git a/subjects/btreeapplypreorder/README.md b/subjects/btreeapplypreorder/README.md
index b60cd9a5..5c9f154a 100644
--- a/subjects/btreeapplypreorder/README.md
+++ b/subjects/btreeapplypreorder/README.md
@@ -2,7 +2,11 @@
 
 ### Instructions
 
-Write a function that applies a function using a preorder walk to each element in the tree.
+Write a function that applies a given function `f` to each element in the tree using a preorder walk.
+
+### Notions
+
+- [Tree Traversal](https://en.wikipedia.org/wiki/Tree_traversal)
 
 ### Expected function