diff --git a/client/src/pages/guide/english/redux/redux-middleware/index.md b/client/src/pages/guide/english/redux/redux-middleware/index.md
index 69348facc9..3ee759775e 100644
--- a/client/src/pages/guide/english/redux/redux-middleware/index.md
+++ b/client/src/pages/guide/english/redux/redux-middleware/index.md
@@ -1,5 +1,5 @@
 ---
-title: Redux Middleware	
+title: Redux Middleware
 ---	
  ## Introduction
  In this guide it will be presented to the reader the basic concept of Redux Middleware.
diff --git a/client/src/pages/guide/english/redux/redux-selectors/index.md b/client/src/pages/guide/english/redux/redux-selectors/index.md
index 4056015c06..2b60223110 100644
--- a/client/src/pages/guide/english/redux/redux-selectors/index.md
+++ b/client/src/pages/guide/english/redux/redux-selectors/index.md
@@ -1,15 +1,142 @@
 ---
 title: Redux Selectors
 ---
+
 ## Redux Selectors
 
-This is a stub. <a href='https://github.com/freecodecamp/guides/tree/master/src/pages/redux/redux-selectors/index.md' target='_blank' rel='nofollow'>Help our community expand it</a>.
+Redux selectors in their essence are functions that are used to select a subset of data from a Redux state, or in Redux terms, calculate derived data.
 
-<a href='https://github.com/freecodecamp/guides/blob/master/README.md' target='_blank' rel='nofollow'>This quick style guide will help ensure your pull request gets accepted</a>.
+These functions take a state as an argument and make some computations and then return the data that is going to be passed down to any given component.
 
-<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
+
+## Why use this pattern
+
+One reason for using this pattern is to avoid duplicate data.
+
+Given that we have a list of items in Redux, and we only need to show a filtered list. 
+
+A naive approach with Redux would be to filter the list, store it in Redux and then pass it along to the specific component.
+
+With this approach we would have two copies of the items and would be easier for the data to get out of sync. 
+
+In case of any operation on the data it would be necessary to make the update twice.
+
+Another naive approach would be to transform the data directly in the component making use of Redux mapStateToProps like how it's shown in the code bellow.
+
+
+```javascript
+ // reducer
+ const listofItems=(state={items:[]},action)=>{
+     switch(action.type){
+         case "SHOW_ALL":
+            return action.data.items;
+         default:
+            return state;
+     }
+ };
+```
+The items stored could be something like:
+
+```javascript
+{
+    id:1,
+    text:"Lorem ipsum dolor sit amet",
+    complete:false
+}
+```
+```javascript
+    import React, { Component } from "react";
+    import {connect} from "react-redux";
+
+    class ItemShow extends Component{
+        render(){
+            const {incompleteItems}= this.props
+            return (
+                <ul>
+                    {
+                        incompleteItems.map(item=>(
+                            <li key={item.id}>
+                                {item.text}
+                            </li>
+                        ))
+                    }
+                </ul>
+            )
+        }
+    }
+    const mapStateToProps =(state)=>{
+        return {
+            incompleteItems:state.listofItems.filter(item=>{
+                return !item.complete
+            });
+        }
+    };
+    export default connect(mapStateToProps,null)(ItemShow);
+```
+With this it would make the components more coupled to the Redux state and less generic and reusable.
+
+Also it would impact the performance of the application, because the mapStateToProps function gets called alot during the lifecycle of the application and using it for this type of calculation is not a good practice.
+
+## Selector function in action
+
+To solve the problem above a selector function is going to be created.
+
+As per good practices, this function should be near the reducer
+
+Expanding the example above, now the reducer would be something like the code bellow.
+
+```javascript
+ // reducer
+ const listofItems=(state={items:[]},action)=>{
+     switch(action.type){
+         case "SHOW_ALL":
+            return action.data.items;
+         default:
+            return state;
+     }
+ };
+ 
+ const getIncompleteItems=state=>{
+     const {listofItems}=state;
+     return listofItems.filter(item=>{
+         return !item.complete
+     });
+ }
+```
+
+And the component would look like something like this
+```javascript
+    import React, { Component } from "react";
+    import {connect} from "react-redux";
+
+    class ItemShow extends Component{
+        render(){
+            const {incompleteItems}= this.props
+            return (
+                <ul>
+                    {
+                        incompleteItems.map(item=>(
+                            <li key={item.id}>
+                                {item.text}
+                            </li>
+                        ))
+                    }
+                </ul>
+            )
+        }
+    }
+    const mapStateToProps =(state)=>{
+        return {
+            incompleteItems:getIncompleteItems(state);
+        }
+    };
+
+    export default connect(mapStateToProps,null)(ItemShow);
+```
 
 #### More Information:
-<!-- Please add any articles you think might be helpful to read before writing the article -->
+[Simple reselect explanation](https://guide.freecodecamp.org/redux/reselect)
+
+[reselect official documentation](https://guide.freecodecamp.org/redux/reselect)