Altogether 9 different volumes, including: Aviation school and modern aircraft in words and pictures by Hans Erblich, each Berlin 1914, The America flight of the ZR III by A. Wittemann, Wiesbaden 1925, engines for aircraft and airships by Fritz Huth, Berlin 1914 , In a large plane to Pekin, by Robert Knauß, Berlin oJ, pilot's manual by Robert Eyb, Berlin 1914, on air patrol and world tour by Ernst A. Lehmann, Berlin 1936, South Atlantic flight by Fischer von Poturzyn, Munich 1934, and flight to America by Francesco de Pinedo, Leipzig and Stuttgart 1928, differ. signs of age
