Ulamec, S.; Espinasse, S.; Feuerbacher, B.; Hilchenbach, M.; Moura, D. et al. (April 2006). "Rosetta Lander—Philae: Implications of an alternative mission". Acta Astronautica58 (8): 435–441. doi:10.1016/j.actaastro.2005.12.009. Bibcode: 2006AcAau..58..435U.
Ulamec, S.; Espinasse, S.; Feuerbacher, B.; Hilchenbach, M.; Moura, D. et al. (April 2006). "Rosetta Lander—Philae: Implications of an alternative mission". Acta Astronautica58 (8): 435–441. doi:10.1016/j.actaastro.2005.12.009. Bibcode: 2006AcAau..58..435U.