diff --git a/README-jp.md b/README-jp.md
index 7b8c53c..3f5f925 100644
--- a/README-jp.md
+++ b/README-jp.md
@@ -275,6 +275,7 @@ If you enjoy this awesome list and would like to support it, check out my [Patre
 ### SSL/TLS
 
 - [SSL & TLS Penetration Testing](https://www.aptive.co.uk/blog/tls-ssl-security-testing/) - Written by [APTIVE](https://www.aptive.co.uk/).
+- [Practical introduction to SSL/TLS](https://github.com/Hakky54/mutual-tls-ssl) - Written by [@Hakky54](https://github.com/Hakky54).
 
 <a name="webmail"></a>
 ### Webmail
diff --git a/README-zh.md b/README-zh.md
index a1b5c0b..a71cd7e 100644
--- a/README-zh.md
+++ b/README-zh.md
@@ -293,6 +293,7 @@ If you enjoy this awesome list and would like to support it, check out my [Patre
 ### SSL/TLS
 
 - [SSL & TLS Penetration Testing](https://www.aptive.co.uk/blog/tls-ssl-security-testing/) - Written by [APTIVE](https://www.aptive.co.uk/).
+- [Practical introduction to SSL/TLS](https://github.com/Hakky54/mutual-tls-ssl) - Written by [@Hakky54](https://github.com/Hakky54).
 
 <a name="webmail"></a>
 ### Webmail
diff --git a/README.md b/README.md
index 81e707e..9c73ea1 100644
--- a/README.md
+++ b/README.md
@@ -272,6 +272,7 @@ If you enjoy this awesome list and would like to support it, check out my [Patre
 ### SSL/TLS
 
 - [SSL & TLS Penetration Testing](https://www.aptive.co.uk/blog/tls-ssl-security-testing/) - Written by [APTIVE](https://www.aptive.co.uk/).
+- [Practical introduction to SSL/TLS](https://github.com/Hakky54/mutual-tls-ssl) - Written by [@Hakky54](https://github.com/Hakky54).
 
 <a name="webmail"></a>
 ### Webmail