Orbital elements of the material surrounding comet 67P/Churyumov-Gerasimenko B. J. R. Davidsson, P. J. Gutiérrez, H. Sierks, C. Barbieri, P. L. Lamy, R. Rodrigo, D. Koschny, H. Rickman, H. U. Keller, J. Agarwal et al. (37 more) A&A, 583 (2015) A16 Published online: 30 October 2015 DOI: 10.1051/0004-6361/201525841