Cowell, C. (2019). Knock three times (First U.S. edition.). Little, Brown, and Company.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCowell, Cressida. Knock Three Times. First U.S. edition. New York: Little, Brown, and Company, 2019.
एमएलए (8वां संस्करण) प्रशस्ति पत्रCowell, Cressida. Knock Three Times. First U.S. edition. Little, Brown, and Company, 2019.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.