@article{1365935,
      note = {"November 1998, volume 136, number 650 (fifth of 6  numbers)."},
      author = {Musson, Ian M. and Bergh, M. van den,},
      url = {http://library.usi.edu/record/1365935},
      title = {Invariants under tori of rings of differential operators  and related topics /},
      recid = {1365935},
      pages = {1 online resource (99 pages) :},
}