@misc{indiciae6c2b6c10f7cf,
  title = {Contamination of mars},
  author = {Lederberg, J. and Levinthal, E. C. and Sagan, C.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19670031109},
  note = {Source identifier: 19670031109}
}