@article{Pilawa:2009,
author
=
"B.Pilawa and A.Więckowski",
title
=
"Groups of paramagnetic centres in coal samples with different carbon contents",
journal
=
"Research on Chemical Intermediates",
volume
=
"Vol. 33",
number
=
"no 8-9",
pages
=
"825--839",
year
=
"2007",
}