@article{18219,
      author = {Maher, Thomas Patrick.},
      url = {http://library.usi.edu/record/18219},
      title = {Acidic structural groups in Illinois coals; variation  during oxidation and carbonization},
      publisher = {Illinois State Geological Survey,},
      recid = {18219},
      pages = {75 p.},
      address = {Urbana,},
      year = {1959},
}