GSGS series 4414. Sheet 3010, Second Edition (A.E.F.). First edition copied from German Topographisce Karte 1:25,000 Sheet 3010 dated 1934 and photolithographed by the British Ordnance Survey in 1944. Second edition revised from air photographs October 1944 by 21 A. Gp Air Survey Group. Lambert modified conical orthomorphic projection. Nord de Guerre Grid.