Williamson, M. Z. (2022). That was now, this is then. Baen.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWilliamson, Michael Z. That Was Now, This Is Then. New York: Baen, 2022.
एमएलए (8वां संस्करण) प्रशस्ति पत्रWilliamson, Michael Z. That Was Now, This Is Then. Baen, 2022.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.