Pratt, G. J., Lambrou, P. T., & Mann, J. D. (2012). Code to joy: The four-step solution to unlocking your natural state of happiness. HarperOne.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPratt, George J., Peter T. Lambrou, और John David Mann. Code to Joy: The Four-step Solution to Unlocking Your Natural State of Happiness. New York: HarperOne, 2012.
एमएलए (8वां संस्करण) प्रशस्ति पत्रPratt, George J., et al. Code to Joy: The Four-step Solution to Unlocking Your Natural State of Happiness. HarperOne, 2012.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.