@article{295256,
      author = {Davidson, Keay. and Sagan, Carl,},
      url = {http://library.usi.edu/record/295256},
      title = {Carl Sagan : a life /},
      publisher = {J. Wiley,},
      recid = {295256},
      pages = {xx, 540 p. ;},
      address = {New York :},
      year = {1999},
}