Cita APA (7th ed.)

Keene, C. (1981). The clue in the crossword cipher. Armada books.

Cita Chicago (17th ed.)

Keene, Carolyn. The Clue in the Crossword Cipher. New York: Armada books, 1981.

Cita MLA (9th ed.)

Keene, Carolyn. The Clue in the Crossword Cipher. Armada books, 1981.