Columbia subject headings:
Harvard subject headings:
Hirschfeld, Wolfgang, 1916-
Submarines (Ships)--Germany
World War, 1939-1945--Naval operations--Submarine.
World War, 1939-1945--Personal narratives, German.
Princeton subject headings:
Hirschfeld, Wolfgang, 1916-
Submarines (Ships)--Germany.
World War, 1939-1945--Naval operations--Submarine.
World War, 1939-1945--Personal narratives, German.