app/views/project_sources/_quick_search_form.html.erb
<%= form_tag(search_sources_path, {method: :get}) do %>
<%= render 'workbench/elements/forms/ajax_select',
controller: '/project_sources',
object: nil,
autofocus: true,
send_select: true,
method: 'id',
tag_id: 'source_id_for_project_source_quick_search_form'
%>
<%= submit_tag 'Show' %>
<% end %>