Grabenkarten.1918?]Legend indicates trench information in red and blue ink.Northeast, northwest, and southwest corners of Bl. 142, Bernécourt.Northeastern sheet: "Abgeschlossen am 10.6.18"; Northwestern sheet: "Abgeschlossen am 20.5.18"; Southwestern sheet: "Abgeschlosse am 20.5.18"; Southwestern sheet: "Abgeschlossen am 17.6.18".cartographic