v.d. Giessen & Zonens Scheepwerfen was a Norwegian shipbuilding
company, located in Krimpen a/d Ijssel, Ships and U-boats
built by v.d. Giessen & Zonens Scheepwerfen 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