Elementry map and aerial photography reading - USA Voorschrift, Field Manual Advanced map and aerial photograph reading - USA Voorschrift, Field Manual, 21-26 Advanced map and aerial photograph reading - USA Basic Field Manual, FM 21-26 Elementary map and aerial photograph reading - USA Voorschrift, Basic Field Manual, 21-25 Symbols for seacoast defense fire-control maps, diagrams, and structures - USA Voorschrift, Technical Regulations, No.