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  Secret U-Boat Ops

  http://www.german-navy.de/kriegsmarine/articles/feature2.html

  The German Kriegsmarine, Secret U-Boat Ops, The German Kriegsmarine, Articles

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  The Siege of Constantinople (1453), according to Nicolo Barbaro

  https://web.archive.org/web/20111218201430/http://www.deremilitari.org/resources/sources/constantinople3.htm

  Keine Beschreibung vorhanden.

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