@article{289216,
      note = {"February 2001."},
      author = {Portree, David S. F.},
      url = {http://library.usi.edu/record/289216},
      title = {Humans to Mars fifty years of mission planning, 1950-2000  / [microform] :},
      publisher = {NASA History Division, Office of Policy and Plans, NASA  Headquarters,},
      recid = {289216},
      pages = {vii, 152 p. :},
      address = {Washington, DC :},
      year = {2001},
}