proper exist problem1

src/app/admin-add/admin-add.component.html

@@ -5,47 +5,47 @@
   <div class="form-group">
     <label for="Input2">Book name</label>
     <input type="text" class="form-control" placeholder="Book name"
-      name="name" [(ngModel)]="book.name">
+       [(ngModel)]="book.name">
   </div>
   <div class="form-group">
       <label for="Input10">Authors</label>
       <input type="text" class="form-control" placeholder="Authors"
-        name="isolatedAuthorNames" [(ngModel)]="book.isolatedAuthorNames">
+         [(ngModel)]="book.isolatedAuthorNames">
     </div>
   <div class="form-group">
       <label for="Input9">Abstract</label>
       <textarea class="form-control bkl-textarea" placeholder="Abstract (HTML syntax supported)"
-        name="abstract" [(ngModel)]="book.abstract"></textarea>
+         [(ngModel)]="book.abstract"></textarea>
     </div>
   <div class="form-group">
     <label for="Input3">ISBN</label>
     <input type="text" class="form-control" placeholder="ISBN"
-      name="ISBN" [(ngModel)]="book.ISBN">
+       [(ngModel)]="book.ISBN">
   </div>
   <div class="form-group">
     <label for="Input4">Rating</label>
     <input type="number" class="form-control" placeholder="Rating"
-      name="rating" [(ngModel)]="book.rating">
+       [(ngModel)]="book.rating">
   </div>
   <div class="form-group">
     <label for="Input5">Publish Year</label>
     <input type="number" class="form-control" placeholder="Publish Year"
-      name="publishYear" [(ngModel)]="book.publishYear">
+       [(ngModel)]="book.publishYear">
   </div>
   <div class="form-group">
     <label for="Input6">Pages</label>
     <input type="number" class="form-control" placeholder="Pages"
-      name="pages" [(ngModel)]="book.pages">
+       [(ngModel)]="book.pages">
   </div>
   <div class="form-group">
     <label for="Input7">Books Categories</label>
     <input type="string" class="form-control" placeholder="Books Categories (separated with commas)"
-      name="tags_z" [(ngModel)]="tags_z">
+       [(ngModel)]="tags_z">
   </div>
   <div class="form-group">
     <label for="Input8">Book Link</label>
     <input type="text" class="form-control" placeholder="Book Link"
-      name="link" [(ngModel)]="book.link">
+       [(ngModel)]="book.link">
   </div>
   
   <button type="submit" class="btn btn-primary mb-2" (click)="onAdd()">Add</button>

src/app/collectionitem/collectionitem.component.html

@@ -8,7 +8,7 @@
     <div class="card-body">
       <h6 class="card-subtitle mb-2 text-muted">rating: {{ book.rating }}</h6>
       <p class="card-text"><b>Abstract:</b> {{ book.abstract }}}</p>
-      <a class="card-link"><b>Authors:</b> {{ authorNames }}</a>
+      <!-- <a class="card-link"><b>Authors:</b> {{ authorNames }}</a> -->
     </div>
   </div>
   <button *ngIf="isOwnCollection" type="button" class="btn btn-outline-primary btn-sm"