@article{Duber:2009,
author
=
"S.Duber and H.Wachowska and A.Więckowski",
title
=
"E.p.r. study of reduced and reductively ethylated coals",
journal
=
"Fuel",
volume
=
"Vol. 66",
number
=
"no 8",
pages
=
"1069--1072",
year
=
"1987",
}