Proceedings of ECOpole
Proceedings of ECOpole > 2015 > Vol. 9, No. 2 > 667--675
Proceedings of ECOpole > 2015 > Vol. 9, No. 2 > 483--488
Proceedings of ECOpole > 2015 > Vol. 9, No. 2 > 667--675
Proceedings of ECOpole > 2015 > Vol. 9, No. 2 > 483--488