How to delete a reference order on order detail

[Roman0002]

Hello,

 

Where do I find a file which I delete order reference.

I want to delete from the places marked with a red rectangle.

The file order.tpl, view.tpl and ordercontroller.php it is not ...

 

For help and answers thank you in advance.

[vekia]

/controllers/admin/AdminOrdersController.php

$this->toolbar_title[] = sprintf($this->l('Order %1$s from %2$s %3$s'), $order->reference, $customer->firstname, $customer->lastname);