@article{N 94-33533,
      recid = {179473},
      author = {DeVincenzi, Donald L. and Klein, Harold P. and Bagby, John  R.},
      title = {Planetary protection issues and future Mars missions  [microform] /},
      publisher = {National Aeronautics and Space Administration, Ames  Research Center ;},
      address = {Moffett Field, Calif. :},
      number = {N 94-33533},
      pages = {1 v.},
      year = {1991},
      note = {Distributed to depository libraries in microfiche.},
      url = {http://library.usi.edu/record/179473},
}