APA
Keene C., . (1971). The clue in the crossword ciper. Armada, London: .
Chicago
Keene Carloyn, . 1971. The clue in the crossword ciper. Armada, London: .
Harvard
Keene C., . (1971). The clue in the crossword ciper. Armada, London: .
MLA
Keene Carloyn, . The clue in the crossword ciper. Armada, London: . 1971.