Is it possible to list the invoices with two criterias, filterby and customerid?? 

GET  /invoices?customer_id={customer_id}?filter_by={sent}

It would be a good improvement, because we need to reduce the API limits or another way to do it, will be list the invoices between two dates or list the invoices from one date.

GET  /invoices?dateStart={dateX}?dateEnd={dateY} or  GET  /invoices?duedate={date}

Best regards,