@article{172829,
      note = {Includes index.},
      author = {Bradley, Raymond. and Swartz, Norman,},
      url = {http://library.usi.edu/record/172829},
      title = {Possible worlds : an introduction to logic and its  philosophy /},
      publisher = {Hackett Pub. Co.,},
      recid = {172829},
      pages = {xxi, 391 p. :},
      address = {Indianapolis :},
      year = {1979},
}