Erikson, A., Skoglöv, E. (2003): Planetary spin-axis evolution in the 47 UMa habitable zone. Toward other Earths - Darwin/TPF and the Search for Extrasolar Terrestrial Planets, Proceedings, April 22-25 2003, Heidelberg, Germany, ESA SP-539, 409.
Rauer, H., Helbert, J., Arpigny, C., Benkhoff, J., Bockelee-Morvan, D., Boehnhardt, H., Colas, F., Crovisier, J., Hainaut, O., Jorda, L., Kueppers, J., Manfroid, J., Thomas, N. (2003): Long-term optical spectrophotometric monitoring of comet C/1995 O1 (Hale-Bopp), Astronomy and Astrophysics 397, 1109.
Weiler, M.; Rauer, H., Knollenberg, J., Jorda, L., Helbert, J. (2003): The dust activity of comet C/1995 O1 (Hale-Bopp) between 3 AU and 13 AU from the Sun, Astronomy and Astrophysics 403, 313.