AMS series M841. Sheet 4003, Second Edition (A.E.F.). Copied from Netherland Topografische Inrichting 1:25,000 dated 1930-31 and Topografische Inrichting 1:50,000 dated 1932. Revised from air photographs from 1940 and 1943 in October 1944 by the 21 A.Gp. Air Survey Group. Polyconic projection. Contour interval at 10 metres. Nord de Guerre Grid.