@misc{indiciae39afb2d53e7a,
  title = {Mars Surface Tunnel Element Concept},
  author = {Rucker, Michelle A. and Jefferies, Sharon and Howe, A. Scott and Howard, Robert and Mary, Natalie and Watson, Judith and Lewis, Ruthan},
  year = {2016},
  url = {https://ntrs.nasa.gov/citations/20160001028},
  note = {Source identifier: 20160001028}
}