@article{Pilawa:2009,
author
=
"B.Pilawa and A.Więckowski and R.Pietrzak and H.Wachowska",
title
=
"Influence of oxidation on paramagnetic centers of coal",
journal
=
"Karbo",
volume
=
"R. 46",
number
=
"nr 11",
pages
=
"382--385",
year
=
"2001",
}