diff --git a/subjects/advancedsortwordarr/README.md b/subjects/advancedsortwordarr/README.md
index 72d34ef62..05b09c405 100644
--- a/subjects/advancedsortwordarr/README.md
+++ b/subjects/advancedsortwordarr/README.md
@@ -40,3 +40,9 @@ $ go run .
 [1 2 3 A B C a b c]
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)
diff --git a/subjects/any/README.md b/subjects/any/README.md
index 81c74accd..62490c032 100644
--- a/subjects/any/README.md
+++ b/subjects/any/README.md
@@ -46,3 +46,9 @@ false
 true
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)
diff --git a/subjects/countif/README.md b/subjects/countif/README.md
index 7c96f2ee4..c9c0f1d54 100644
--- a/subjects/countif/README.md
+++ b/subjects/countif/README.md
@@ -42,3 +42,9 @@ $ go run .
 2
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)
diff --git a/subjects/doop/README.md b/subjects/doop/README.md
index e543c0bd6..b6967dfcc 100644
--- a/subjects/doop/README.md
+++ b/subjects/doop/README.md
@@ -35,3 +35,8 @@ $ go run . 1 "*" -1
 -1
 $
 ```
+
+### Notions
+
+- [Numeric Types](https://golang.org/ref/spec#Numeric_types)
+- [Arithmetic Operators](https://golang.org/ref/spec#Arithmetic_operators)
diff --git a/subjects/foreach/README.md b/subjects/foreach/README.md
index 7c46979f3..e6342c053 100644
--- a/subjects/foreach/README.md
+++ b/subjects/foreach/README.md
@@ -34,3 +34,9 @@ $ go run .
 123456
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)
diff --git a/subjects/issorted/README.md b/subjects/issorted/README.md
index f949b257d..a09abfd58 100644
--- a/subjects/issorted/README.md
+++ b/subjects/issorted/README.md
@@ -48,3 +48,9 @@ true
 false
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)
diff --git a/subjects/map/README.md b/subjects/map/README.md
index 85660ade2..63c0966f7 100644
--- a/subjects/map/README.md
+++ b/subjects/map/README.md
@@ -38,3 +38,9 @@ $ go run .
 [false true true false true false]
 $
 ```
+
+### Notions
+
+- [Function literals](https://golang.org/ref/spec#Function_literals)
+- [Function declaration](https://golang.org/ref/spec#Function_declarations)
+- [Function types](https://golang.org/ref/spec#Function_types)