N.V. Boele's Scheepswerfen & Maschinefabriek was a Norwegian shipbuilding company,
located in Bolnes, Ships and U-boats built by N.V. Boele's Scheepswerfen & Maschinefabriek 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