Columbia subject headings:
Cryptography--Early works to 1800.
Language and languages.
Philosophy--Miscellanea.
Harvard subject headings:
Cryptography--Early works to 1800
Language and languages.
Philosophy--Miscellanea
Princeton subject headings:
Cryptography--Early works to 1800.
Language and languages.
Philosophy--Miscellanea.
Trivia and miscellanea.