can add relation between co-author

app/views/desktop/co_author_relations/_form.html.erb

@@ -0,0 +1,4 @@
+<%= form_for(@new_relation , url: desktop_co_author_relations_path ) do |f| %>
+    <%= f.text_field :relation %>
+    <%= f.submit "Save" %>
+<% end %>

app/views/desktop/co_author_relations/index.html.erb

@@ -0,0 +1,18 @@
+<h1>Listing co_author_relations</h1>
+
+<%= render 'form' %>
+
+<table>
+  <tr>
+    <th>Relation</th>
+    <th></th>
+    <th></th>
+  </tr>
+
+<% @co_author_relations.each do |co_author_relation| %>
+  <tr>
+    <td><%= co_author_relation.relation %></td>
+    <td><%= link_to 'Destroy', desktop_co_author_relation_path(co_author_relation), confirm: 'Are you sure?', method: :delete %></td>
+  </tr>
+<% end %>
+</table>

app/views/desktop/co_authors/index.html.erb

@@ -1,6 +1,6 @@
 <h1>list all coauthor</h1>
 <%= link_to "New Co-Author", new_desktop_co_author_path %>
-<%= link_to "New Type", "#" %>
+<%= link_to "New Type",  desktop_co_author_relations_path %>
 <table>
   <tr>
     <th>Name</th>