France, 1:25,000. Sheet no. 31/20 S.E., Montebourg.
MLA
France, 1:25,000. Sheet No. 31/20 S.E., Montebourg. s.n., 1944. https://collections.library.yale.edu/catalog/15238349.
APA, 6th edition
France, 1:25,000. Sheet no. 31/20 S.E., Montebourg. (1944). [Maps]. s.n., https://collections.library.yale.edu/catalog/15238349.