diff --git a/.all-contributorsrc b/.all-contributorsrc
index 6c2bbadbc..3e0200276 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -1268,6 +1268,24 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "OrangePants-R",
+      "name": "Rocky",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/42976136?v=4",
+      "profile": "https://github.com/OrangePants-R",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "ibrahimAlii",
+      "name": "Ibrahim ali abdelghany",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/21141301?v=4",
+      "profile": "https://ibrahimalii.github.io/",
+      "contributions": [
+        "review"
+      ]
     }
   ],
   "contributorsPerLine": 4,
diff --git a/README.md b/README.md
index 4211060c5..46387b058 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@
 [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=coverage)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-104-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-141-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # Introduction
@@ -277,6 +277,10 @@ This project is licensed under the terms of the MIT license.
     <td align="center"><a href="https://github.com/akashchandwani"><img src="https://avatars2.githubusercontent.com/u/3483277?v=4" width="100px;" alt=""/><br /><sub><b>Akash Chandwani</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aakashchandwani" title="Reviewed Pull Requests">👀</a></td>
     <td align="center"><a href="http://www.linkedin.com/in/manannikov"><img src="https://avatars2.githubusercontent.com/u/7019769?v=4" width="100px;" alt=""/><br /><sub><b>Pavlo Manannikov</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=manannikov" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/eimanip"><img src="https://avatars0.githubusercontent.com/u/20307301?v=4" width="100px;" alt=""/><br /><sub><b>Eiman</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=eimanip" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/OrangePants-R"><img src="https://avatars0.githubusercontent.com/u/42976136?v=4" width="100px;" alt=""/><br /><sub><b>Rocky</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=OrangePants-R" title="Documentation">📖</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://ibrahimalii.github.io/"><img src="https://avatars2.githubusercontent.com/u/21141301?v=4" width="100px;" alt=""/><br /><sub><b>Ibrahim ali abdelghany</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AibrahimAlii" title="Reviewed Pull Requests">👀</a></td>
   </tr>
 </table>
 
diff --git a/iterator/README.md b/iterator/README.md
index 71ad807cd..c0e166b69 100644
--- a/iterator/README.md
+++ b/iterator/README.md
@@ -140,6 +140,10 @@ Use the Iterator pattern
 * To support multiple traversals of aggregate objects.
 * To provide a uniform interface for traversing different aggregate structures.
 
+## Tutorials
+
+* [How to Use Iterator?](http://www.tutorialspoint.com/java/java_using_iterator.htm)
+
 ## Real world examples
 
 * [java.util.Iterator](http://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html)