partner_account_statement/template.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
  <data>
    <template id="assets_backend" name="board assets" inherit_id="web.assets_backend">
      <xpath expr="." position="inside">
        <link rel="stylesheet" href="/partner_account_statement/static/src/css/custom.css"/>
        <script type="text/javascript" src="/partner_account_statement/static/src/js/report_account_statement.js"/>
      </xpath>
    </template>
  </data>
</openerp>