20.O35 [Bourbaki Cross Roads, Houthulst Forest] December 10, 1917
Covers an area equivalent to portions of squares O29, 34, and 35 on the corresponding WWI map sheet 20. Negative roll 9B, photo 134. Annotations on recto: north arrow pointing to the upper-left with an "x" on the opposite edge of the photo. WWI Aerial Photograph Collection: Box 3, Envelope 45.