@misc{indiciae155f719708e3,
  title = {The study of comets, part 1},
  author = {Donn, B. and Mumma, M. J. and Jackson, W. M. and Ahearn, M. and Harrington, R.},
  year = {1976},
  url = {https://ntrs.nasa.gov/citations/19760013964},
  note = {Source identifier: 19760013964}
}