@article{Szelecka:2009,
author
=
"A.Szelecka and A.Włoch",
title
=
"A note on strong and co-strong perfectness of the X-join graphs",
journal
=
"Discussiones Mathematicae - Graph Theory",
volume
=
"Vol. 16",
number
=
"no 2",
pages
=
"151--155",
year
=
"1996",
}