20.O16 [Between Strovendorp and Pierkenshoek] December 26, 1917
Covers an area equivalent to portions of squares O16 and 17 on the corresponding WWI map sheet 20. Negative roll 9B, photo 214. Brass Cross Roads in square O17 is at the upper-right of the photo near the white air photo referencing numbers. Annotations on recto: north arrow pointing to the upper-left. WWI Aerial Photograph Collection: Box 1, Envelope 73.