Howaldtswerke AG was a German shipbuilding company, located
in Kiel. and was founded in 1838, Ships and U-boats built
by Howaldtswerke AG include.
German Warships, 1815-1945: Major Surface Vessels.
German Warships, 1815-1945: U-boats and Mine Warfare Vessels.
German warships of the Second World War.
For a complete list of sources