@misc{1200071,
  author = {Jim Lawrence},
  title = {Finite unions of closed subgroups of the n-dimensional torus:},
  year = {1988},
  month = {1988-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NIST.IR.88-3777},
  language = {en},
}