Kirkman, R. (2015). Invincible (2003), volume 11: Happy days (Collected.). Image Comics.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रKirkman, Robert. Invincible (2003), Volume 11: Happy Days. Collected. Cleveland: Image Comics, 2015.
एमएलए (8वां संस्करण) प्रशस्ति पत्रKirkman, Robert. Invincible (2003), Volume 11: Happy Days. Collected. Image Comics, 2015.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.