diff --git a/.gitignore b/.gitignore
index 6fee6d3a..2458e8b0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 .idea/*
-*.log
\ No newline at end of file
+*.log
+node_modules
+coverage
diff --git a/README.md b/README.md
index 4e9eca37..64771d99 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ Source code of **Learning JavaScript Data Structures and Algorithms** book.
 
 | 1st edition   | 2nd edition   | 
 | ------------- |:-------------:| 
-| ![1st edition](https://d1ldz4te4covpm.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/4874OS_Learning%20JavaScript%20Data%20Structures%20and%20Algorithms.jpg)      | ![2nd edition](https://dz13w8afd47il.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/B05348_MockupCover_Normal.jpg) | 
+| ![1st edition](https://d1ldz4te4covpm.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/4874OS_Learning%20JavaScript%20Data%20Structures%20and%20Algorithms.jpg)      | ![2nd edition](https://d255esdrn735hr.cloudfront.net/sites/default/files/imagecache/ppv4_main_book_cover/5493OS_5348_Learning%20JavaScript%20Data%20Structures%20and%20Algorithms,%20Second%20Edition.jpg) | 
 | [Book link](http://amzn.to/1Y1OWPx)| [Book link](http://amzn.to/1TSkcA1)|
 
 Book link - first edition:
@@ -17,6 +17,7 @@ Book link - first edition:
 Book link - second edition:
  - [Packt](https://www.packtpub.com/web-development/learning-javascript-data-structures-and-algorithms-second-edition)
  - [Amazon](http://amzn.to/1TSkcA1)
+ - [Brazilian Portuguese version](https://novatec.com.br/livros/estruturas-de-dados-algoritmos-em-javascript/)
 
 ### List of Chapters:
   
diff --git a/chapter01/14-ES6ParameterHandling.js b/chapter01/14-ES6ParameterHandling.js
index 4645f2a7..af23585c 100644
--- a/chapter01/14-ES6ParameterHandling.js
+++ b/chapter01/14-ES6ParameterHandling.js
@@ -14,7 +14,7 @@ function sum2 (x, y, z) {
         z = 3;
     return x + y + z;
 };
-console.log(sum2(4,2)); //outpus 10
+console.log(sum2(4,2)); //outpus 9
 
 //******* EcmaScript 6: spread operator ('...')
 var params = [3, 4, 5];
diff --git a/chapter02/06-ES6Methods.js b/chapter02/06-ES6Methods.js
index 60468aa4..bf4eb36a 100644
--- a/chapter02/06-ES6Methods.js
+++ b/chapter02/06-ES6Methods.js
@@ -40,7 +40,7 @@ console.log(aKeys.next()); // {value: 1, done: false }
 console.log(aKeys.next()); // {value: 2, done: false }
 
 console.log('Array.values');
-//let aValues = numbers.values();
+let aValues = numbers.values();
 console.log(aValues.next()); // {value: 1, done: false } done false means iterator has more values
 console.log(aValues.next()); // {value: 2, done: false }
 console.log(aValues.next()); // {value: 3, done: false }
diff --git a/chapter05/05-CircularLinkedList.js b/chapter05/05-CircularLinkedList.js
index 5f05e85f..c3151148 100644
--- a/chapter05/05-CircularLinkedList.js
+++ b/chapter05/05-CircularLinkedList.js
@@ -46,16 +46,22 @@ function CircularLinkedList() {
                 index = 0;
 
             if (position === 0){ //add on first position
-
-                node.next = current;
-
-                //update last element
-                while(current.next !== head){ //last element will be head instead of NULL
-                    current = current.next;
+                
+                if(!head){ // if no node  in list
+                    head = node;
+                    node.next = head;
+                }else{
+                    node.next = current;
+
+                    //update last element
+                    while(current.next !== head){ //last element will be head instead of NULL
+                        current = current.next;
+                    }
+
+                    head = node;
+                    current.next = head;
                 }
-
-                head = node;
-                current.next = head;
+                
 
             } else {
                 while (index++ < position){
@@ -180,4 +186,5 @@ function CircularLinkedList() {
     this.print = function(){
         console.log(this.toString());
     };
-}
\ No newline at end of file
+}
+
diff --git a/chapter05/05-CircularLinkedList2.js b/chapter05/05-CircularLinkedList2.js
index 5aab62d0..6f7574ef 100644
--- a/chapter05/05-CircularLinkedList2.js
+++ b/chapter05/05-CircularLinkedList2.js
@@ -58,15 +58,18 @@ let CircularLinkedList2 = (function () {
 
               if (position === 0) { //add on first position
 
-                    node.next = current;
-
-                    //update last element
-                    while (current.next !== this.getHead()) { //last element will be head instead of NULL
-                        current = current.next;
-                    }
-
-                    head.set(this, node);
-                    current.next = this.getHead();
+                  if(!this.getHead()) { // if no node  in list
+                      head.set(this, node);
+                      node.next = this.getHead();
+                  } else {
+                      node.next = current;
+                      //update last element
+                      while(current.next !== this.getHead()) { //last element will be head instead of NULL
+                          current = current.next;
+                      }
+                      head.set(this, node);
+                      current.next = this.getHead();
+                  }
 
                 } else {
                     while (index++ < position) {
diff --git a/chapter07/07-HashCollisionLinearProbing.js b/chapter07/07-HashCollisionLinearProbing.js
index 38b07c0f..4b1172be 100644
--- a/chapter07/07-HashCollisionLinearProbing.js
+++ b/chapter07/07-HashCollisionLinearProbing.js
@@ -53,6 +53,15 @@ function HashLinearProbing(){
                     return table[index].value;
                 }
             }
+        } else { //search for possible deleted value
+            var index = ++position;
+            while (table[index] == undefined || index == table.length ||
+                (table[index] !== undefined && table[index] && table[index].key !== key)){
+                index++;
+            }
+            if (table[index] && table[index].key === key) {
+                return table[index].value;
+            }
         }
         return undefined;
     };
diff --git a/chapter07/08-UsingHashCollisionLinearProbing.js b/chapter07/08-UsingHashCollisionLinearProbing.js
index 902384ee..36a33e61 100644
--- a/chapter07/08-UsingHashCollisionLinearProbing.js
+++ b/chapter07/08-UsingHashCollisionLinearProbing.js
@@ -26,4 +26,12 @@ console.log('**** Remove **** ');
 
 hashLinearProbing.remove('Gandalf');
 console.log(hashLinearProbing.get('Gandalf'));
+hashLinearProbing.print();
+
+console.log('**** Remove Test 2 **** ');
+console.log('Removing Jonathan', hashLinearProbing.remove('Jonathan'));
+console.log('**** Print **** ');
+hashLinearProbing.print();
+console.log('Get Jamie', hashLinearProbing.get('Jamie'));
+console.log('**** Print **** ');
 hashLinearProbing.print();
\ No newline at end of file