{% stylesheets output='css/compressed.css'
                '@AcmeFooBundle/Resources/public/css/mystyle1.css'
                '@AcmeFooBundle/Resources/public/css/mystyle2.css' %}
                {# If your files are in web/css/, call them with: 'css/mystyle.css' #}
    <link rel="stylesheet" href="{{ asset_url }}" type="text/css" media="screen" />
{% endstylesheets %}