I'm trying to search through my invoices and what I want to search by is the equivalent of:

Invoices that are: 

• on or after the self.start_date AND

• on or before the self.end_date AND

• type = out_invoice OR out_refund

I can't quite get the syntax right with the leafs.  I've tried various combinations such as:

self.env['account.invoice'].search([('date_invoice','>=',self.start_date),('date_invoice','<=',self.end_date),('type','=','out_invoice'),'|',('type','=','out_refund')])

What's the proper syntax here?