Main sources
This work is based primarily on the following reference:
[1] Fritz
Köhl, Eberhard Rössler
The Type XXI U-Boat
Anatomy of the Ship
Conway Maritime Press, 1991
ISBN 0-85177-570-5
Introduction by Jak P Mallmann Showell
Also, a number of other sources have been used, in particular:
[2] Tarrant,V.E.
The Last Year of the Kriegsmarine
May 1944 - May 1945
Arms and Armour Press, London, 1994
ISBN1-85409-176-X
[3]
Dan van der Vat
The Atlantic Campaign
The Great Struggle at Sea 1939-1945
Hodder & Stoughton, 1988
ISBN 0-340-37751-8
[4] Eberhard
Rössler
"Die deutschen Uboote und ihre Werften"
Bernard & Graefe Verlag, Koblenz 1990
ISBN 3-7637-5879-8
[5] Fritz Köhl
"Vom Original zum Modell: Uboottyp XXI"
Bernard & Graefe Verlag, Koblenz 1992
ISBN 3-87943-605
[6] Eberhard Rössler,
Fritz Köhl
"Vom Original zum Modell: Uboottyp XXIII"
Bernhard & Graefe Verlag, Koblenz 1993
ISBN 3-7637-6007-5
[7] Eberhard Rössler,
Fritz Köhl
"Vom Original zum Modell: Uboottyp XVII"
Bernard & Graefe Verlag Koblenz 1995
ISBN 3-7637-6009-1