account_invoice_sale_link/account_invoice_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
   Copyright (C) 2014 Akretion (http://www.akretion.com/)
   @author: Alexis de Lattre <alexis.delattre@akretion.com>
   The licence is in the file __openerp__.py
-->

<openerp>
<data>

<record id="invoice_form" model="ir.ui.view">
    <field name="name">account_invoice_sale_link.invoice.form</field>
    <field name="model">account.invoice</field>
    <field name="inherit_id" ref="account.invoice_form"/>
    <field name="arch" type="xml">
        <notebook position="inside">
            <page name="sale_ids" string="Venta">
                <field name="sale_ids"/>
            </page>
        </notebook>
    </field>
</record>

</data>
</openerp>