Base Map of Somme Department: Taken from File No. 74-A-3 / American Commision to Negotiate Peace, War Damages in Allied Countries.
MLA
Base Map of Somme Department: Taken from File No. 74-A-3 / American Commision to Negotiate Peace, War Damages in Allied Countries. The Commission, 1919. https://collections.library.yale.edu/catalog/15238191.
APA, 6th edition
Base Map of Somme Department: Taken from File No. 74-A-3 / American Commision to Negotiate Peace, War Damages in Allied Countries. (1919). [Maps]. The Commission, https://collections.library.yale.edu/catalog/15238191.