Kho, N. D. (2019). The thank-you project: Cultivating happiness one letter of gratitude at a time. Running Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रKho, Nancy Davis. The Thank-you Project: Cultivating Happiness One Letter of Gratitude at a Time. Philadelphia: Running Press, 2019.
एमएलए (8वां संस्करण) प्रशस्ति पत्रKho, Nancy Davis. The Thank-you Project: Cultivating Happiness One Letter of Gratitude at a Time. Running Press, 2019.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.