AMS series M841. Sheet 3404, First Edition-AMS 1. Copied from Netherland Topografische Inrichting 1:25,000 dated 1933-35 and Topografische Inrichting 1:50,000 dated 1934 and 1935. Revised from air photographs from 1941 and 1942 in November 1944 (I RCE). Polyconic projection. Contour interval at 10 metres. Nord de Guerre Grid.