@misc{indiciae004cb3630436,
  title = {Round-Trip Missions to Low-Delta-V Asteroids and Implications for Material Retrieval},
  author = {David F Bender and R Scott Dunbar and David J Ross},
  year = {1979},
  url = {https://ntrs.nasa.gov/citations/19790024062},
  note = {Source identifier: 19790024062}
}