Every product comes with the terms of use/printing permissions clearly stated on the copyright page. That should be more than adequate. However, to be on the safe side, you may want to print out a copy of your receipt and take that with you.
Every product comes with the terms of use/printing permissions clearly stated on the copyright page. That should be more than adequate. However, to be on the safe side, you may want to print out a copy of your receipt and take that with you.