[Posttraumtic stress disorder after deployment of German soldiers: does the risk increase with deployment duration?] - Trautmann, S; Schönfeld, S; Höfler, M; Heinrich, A; Hauffa, R; Zimmermann, P; Wittchen, HU (Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz., 2013)