@misc{indiciaee51263bd7c45,
  title = {The relationship of active comets, 'extinct' comets, and dark asteroids},
  author = {Hartmann, William K. and Tholen, David J. and Cruikshank, Dale P.},
  year = {1987},
  url = {https://ntrs.nasa.gov/citations/19870044305},
  note = {Source identifier: 19870044305}
}