printer_bridge/templates.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>
        <template id="printers_manager_assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <script type="text/javascript" src="/print_engine/static/src/js/main.js" />
                <link rel="stylesheet" href="/print_engine/static/src/css/main.css" />
            </xpath>
        </template>
    </data>
</openerp>