@article{58,
      author = {Willman, H. B.},
      url = {http://library.usi.edu/record/58},
      title = {Bibliography and index of Illinois geology through 1965; a  contribution to the Illinois sesquicentennial year},
      publisher = {Illinois State Geological Survey,},
      recid = {58},
      pages = {373 p.},
      address = {Urbana,},
      year = {1968},
}