Nomenclature 4.0
Nomenclature Primary Object Term
BookNomenclature Sub-Class
Other DocumentsNomenclature Class
Documentary ObjectsNomenclature Category
Category 08: Communication ObjectsSearch Terms
World War, 1939-1945 --Naval operations, German., World War, 1914-1918 --Naval operations, British., World War, 1939-1945 --Cryptography., Submarines (Ships) --Germany --History --20th century., World War, 1939-1945 --Secret service --Great Britain.