Columbia subject headings:
Harvard subject headings:
Cryptographers--Austria--Biography.
Cryptography--Austria--History.
Cryptography--Austria.
Figl, Andreas, 1873-1967.
Figl, Andreas, 1873-1967. Kryptographischen Erinnerungen.
World War, 1914-1918--Cryptography
Princeton subject headings:
Cryptography--Austria--History.
Cryptography--Austria.
Figl, Andreas, 1873-1967.
Figl, Andreas, 1873-1967. Kryptographischen Erinnerungen.