Observer's book of aircraft ; 1973 Observer's book of aircraft ; 1974 Observer's book of aircraft ; 1976 Flugzeuge der Welt : heute morgen World Guide to Combat Planes one War planes of the second World War Fighters volume one War planes of the second World War Fighters volume two War planes of the second World War Fighters volume three War planes of the second World War Fighters volume four War planes of the second World War Flying Boats volume five War planes of the second World War Floatplanes volume six War planes of the second World War Bombers and reconaissance aircraft : volume seven