diff --git a/lib/ext/article.rb b/lib/ext/article.rb
new file mode 100644
index 0000000..ac3d119
--- /dev/null
+++ b/lib/ext/article.rb
@@ -0,0 +1,8 @@
+require_dependency 'article'
+
+class Article
+
+  has_many :states, :through => :article_categorizations, :source => :category, :class_name => State
+  has_many :cities, :through => :article_categorizations, :source => :category, :class_name => City
+
+end
diff --git a/lib/ext/user.rb b/lib/ext/user.rb
index d727f26..1f69e5c 100644
--- a/lib/ext/user.rb
+++ b/lib/ext/user.rb
@@ -34,4 +34,7 @@ class User
     self.person_data[:tipo] = value
   end
 
+  def category_ids= categories
+    self.person_data[:category_ids] = categories
+  end
 end
diff --git a/lib/juventude_plugin/api.rb b/lib/juventude_plugin/api.rb
index 4675874..3267ffc 100644
--- a/lib/juventude_plugin/api.rb
+++ b/lib/juventude_plugin/api.rb
@@ -3,13 +3,13 @@ class JuventudePlugin::API < Grape::API
   resource :states do
 
     get do
-      states = State.select([:id, :name])
+      states = State.select([:id, :name]).order(:name)
       present states
     end
 
     get ':id/cities' do
       state = State.find(params[:id])
-      cities = City.where(:parent_id => state.id).select([:id, :name])
+      cities = City.where(:parent_id => state.id).select([:id, :name]).order(:name)
       present cities
     end
 
--
libgit2 0.21.2