GSGS series 4414. Sheet 2312, Third Edition (A.E.F.). First edition copied from German Topographische Karte 1:25,000 Sheet 2312 dated 1917 and photolithographed by the British Ordnance Survey in 1944. Second edition revised from air photographs December 1944 (I RCE). Third edition revised from air photographs April 1945 (I RCE). Lambert modified conical orthomorphic projection. Nord de Guerre Grid.