Keller, H. U. Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society; MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society;
Richter, K., & Keller, H. U. (1995). On the stability of dust particle orbits around cometary nuclei. Icarus, 114, 355-371.