Proceedings of ECOpole
Proceedings of ECOpole > 2013 > Vol. 7, No. 2 > 685--693
Proceedings of ECOpole > 2013 > Vol. 7, No. 2 > 745--750
Proceedings of ECOpole > 2013 > Vol. 7, No. 2 > 685--693
Proceedings of ECOpole > 2013 > Vol. 7, No. 2 > 745--750