Final answer:
The reference for automated AFTO Form 781 series is found in the guidelines of the US Air Force, used for aircraft maintenance documentation.
Step-by-step explanation:
The reference for automated Air Force Technical Order (AFTO) Form 781 series is provided by the guidelines set forth by the United States Air Force. These automated forms are used for maintenance documentation and management of military aircraft, and their usage is strictly governed by USAF regulations. To find the specific reference, one would typically need to consult the most current Air Force instructions or technical orders that are relevant to maintenance data documentation.