en M.R. Kidger, G. Hurst, N. James, (2004), in: Earth, Moon, and Planets, vol. 78, Nr. 1–3, The Visual Light Curve Of C/1995 O1 (Hale-Bopp) From Discovery To Late 1997Spre text onlineArhivat în , la Wayback Machine.
web.archive.org
en M.R. Kidger, G. Hurst, N. James, (2004), in: Earth, Moon, and Planets, vol. 78, Nr. 1–3, The Visual Light Curve Of C/1995 O1 (Hale-Bopp) From Discovery To Late 1997Spre text onlineArhivat în , la Wayback Machine.