Columbia subject headings:
Cryptographers--United States--Biography.
Cryptography--United States--History.
Friedman, Elizebeth, 1892-1980.
Women--United States--History.
World War, 1914-1918--Cryptography.
Harvard subject headings:
Cryptographers--United States--Biography.
Cryptography--United States--History.
Friedman, Elizebeth, 1892-1980
Women intelligence officers--United States--Biography.
Princeton subject headings:
Cryptographers--United States--Biography.
Cryptography--United States--History.
Friedman, Elizebeth, 1892-1980.
United States. Coast Guard
Women--United States--History.
World War, 1914-1918--Cryptography.