@article{434404,
      recid = {434404},
      title = {Index to the U.S. patent classification [electronic  resource].},
      publisher = {U.S. Dept. of Commerce, Patent and Trademark Office :},
      address = {[Washington, D.C.] :},
      pages = {v. ;},
      note = {Description based on: 1980.},
      url = {http://library.usi.edu/record/434404},
}