diff --git a/docs/README.md b/docs/README.md
index e9ca828..07395a1 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -5,9 +5,6 @@ permalink: /
 # Home
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-1/README.md b/docs/chapter-1/README.md
index 2f08e61..15b98a3 100644
--- a/docs/chapter-1/README.md
+++ b/docs/chapter-1/README.md
@@ -6,9 +6,6 @@ permalink: /chapter-1
 # Chapter 1
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-1/section-1.md b/docs/chapter-1/section-1.md
index fad1c24..be2da1d 100644
--- a/docs/chapter-1/section-1.md
+++ b/docs/chapter-1/section-1.md
@@ -5,9 +5,6 @@ parent: Chapter 1
 # Section 1
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-1/section-2.md b/docs/chapter-1/section-2.md
index 66df93b..4899a66 100644
--- a/docs/chapter-1/section-2.md
+++ b/docs/chapter-1/section-2.md
@@ -5,9 +5,6 @@ parent: Chapter 1
 # Section 2
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-2.md b/docs/chapter-2.md
index 2fd394d..93d41e6 100644
--- a/docs/chapter-2.md
+++ b/docs/chapter-2.md
@@ -4,9 +4,6 @@ nav_order: 3
 # Chapter 2
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-3.md b/docs/chapter-3.md
index 7e1ebda..6b4986b 100644
--- a/docs/chapter-3.md
+++ b/docs/chapter-3.md
@@ -4,9 +4,6 @@ nav_order: 4
 # Chapter 3
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-4/README.md b/docs/chapter-4/README.md
index ee1bf63..64b439c 100644
--- a/docs/chapter-4/README.md
+++ b/docs/chapter-4/README.md
@@ -6,9 +6,6 @@ permalink: /chapter-4
 # Chapter 4
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-4/section-1.md b/docs/chapter-4/section-1.md
index ac9f46a..a9b0f98 100644
--- a/docs/chapter-4/section-1.md
+++ b/docs/chapter-4/section-1.md
@@ -5,9 +5,6 @@ parent: Chapter 4
 # Section 1
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}
 
diff --git a/docs/chapter-4/section-2.md b/docs/chapter-4/section-2.md
index e48d06c..9e02125 100644
--- a/docs/chapter-4/section-2.md
+++ b/docs/chapter-4/section-2.md
@@ -5,9 +5,6 @@ parent: Chapter 4
 # Section 2
 {: .no_toc }
 
-## Table of contents
-{: .no_toc .text-delta }
-
 1. TOC
 {:toc}