old_contents: from django.conf.urls import url
  from api.webview import views
  
  urlpatterns = [
      url(r'^documents/$', views.DocumentList.as_view()),
      url(r'^documents/(.*)/$', views.document_detail, name='document_detail')
  ]
  
new_contents: from django.conf.urls import url
  from api.webview import views
  
  urlpatterns = [
      url(r'^documents/$', views.DocumentList.as_view()),
      url(r'^documents/(?P<source>\w+)/$', views.DocumentsFromSource.as_view(), name='source'),
      url(r'^documents/(?P<source>[a-z]+)/(?P<docID>(.*))/$', views.document_detail, name='document_detail')
  ]
  
subject: add query by source and update detail pattern url