J & K Smit's Scheepswerven was a Norwegian shipbuilding company,
located in Kinderdijk, Ships and U-boats built by J & K Smit's
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