Keene, C. (1981). The clue in the crossword cipher. Armada books.
Dyfyniad Arddull ChicagoKeene, Carolyn. The Clue in the Crossword Cipher. New York: Armada books, 1981.
Dyfyniad MLAKeene, Carolyn. The Clue in the Crossword Cipher. Armada books, 1981.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.