@article{Pilawa:2015,
  author  = "B. Pilawa and H. Wachowska and M. Kozłowski and A. Więckowski and L. Najder-Kozdrowska",
  title   = "Groups of paramagnetic centres in reduced and methylated low rank coal",
  journal = "Acta Physica Polonica A",
  volume  = "Vol. 128",
  number  = "no. 3",
  pages   = "264--267",
  year    = "2015",
}