GSGS series 4414. Sheet 2117, Second Edition (A.E.F.). Copied from German Topographische Karte 1:25,000 Sheet 2117 dated 1933 and photolithographed by the British Ordnance Survey in 1944. Area indicated on reliabilty diagram revised from Air Photographs January 45. by 21 A.Gp Air Survey Group. Revised March 1945 by CDN AIRSVY COY RCE. Lambert modified conical orthomorphic projection. Nord de Guerre Grid.