@misc{indiciae86ecb72d2668,
  title = {Pluto - Evidence for methane frost},
  author = {Cruikshank, D. P. and Pilcher, C. B. and Morrison, D.},
  year = {1976},
  url = {https://ntrs.nasa.gov/citations/19770029547},
  note = {Source identifier: 19770029547}
}