@article{Sonnino08,
  title = {S-spaces from free extensions},
  author = {Angelo Sonnino},
  year = {2008},
  url = {http://cdm.ucalgary.ca/cdm/index.php/cdm/article/view/124},
  researchr = {https://researchr.org/publication/Sonnino08},
  cites = {0},
  citedby = {0},
  journal = {Contributions to Discrete Mathematics},
  volume = {3},
  number = {1},
}